All numbers, notice any relation between the last digit and beginning digits of each numbers ?

[hint]You might want to phone a friend[/hint]

Spoiler

Seeing that end digits of every number is always between 1 and 4 makes it a good candidate for a phone cipher. You’ll need to find the root(n) of x where n is the last digits and x are the rest of the digits for each numbers. Example: 3433 = root(3) of 343 = 7. On a phone 7 has letters PQRS assigned to it, last digit was 3 so the corresponding letter is R.

Number

Root

End Digit

Letter on phone

81

8

1

T

162

4

2

H

3433

7

3

R

92

3

2

E

92

3

2

E

362

6

2

N

252

5

2

K

21

2

1

A

362

6

2

N

643

4

3

I

362

6

2

N

92

3

2

E

71

7

1

P

3433

7

3

R

92

3

2

E

24014

7

4

S

492

7

2

Q

642

8

2

U

92

3

2

E

5123

8

3

V

642

8

2

U

51

5

1

J

362

6

2

N

643

4

3

I

362

6

2

N

92

3

2

E

362

6

2

N

92

3

2

E

643

4

3

I

41

4

1

G

162

4

2

H

81

9

1

T

162

4

2

H

threenkaninepresquevujnineneighth

3nka9presquevuj9n8h

Code #2

Observations

24 characters, seeing some letters that can spell numbers.

Spoiler

Make a 3×8 grid

f

m

k

l

i

o

u

i

u

s

n

w

c

s

h

i

e

t

e

v

n

o

y

i

Not much of a code like this but reading zigzag the first and last column shows good numers.

Reverse rows 2, 4, 6 & 8

f

m

k

o

i

l

u

i

u

w

n

s

c

s

h

t

e

i

e

v

n

i

y

o

Read down

fouwcteimiinsevyklushino

Let’s split things to make it clearer

fou wct ei m ii n sev y klushino

We now get

4wct8m2n7y klushino

Looking up Klushino on Wikipedia gives the birthplace of Yuri Gagarin. Yuri is a valid keyword

4wct8yurim2n7y

Code #3

Observations

Code seems reversed but too many characters in the prefix

[hint]- – There is a substitution in that code but not the keyword…[/hint]

Spoiler

Atbash, ROT and rectangle didn’t give anything good. Time to move on to ciphers like morse, playfair or BiFid.