13655809 has 2 divisors, whose sum is σ = 13655810. Its totient is φ = 13655808.

The previous prime is 13655797. The next prime is 13655819. The reversal of 13655809 is 90855631.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13483584 + 172225 = 3672^2 + 415^2 .

It is a cyclic number.

It is not a de Polignac number, because 13655809 - 2⁹ = 13655297 is a prime.

It is a super-2 number, since 2×13655809² = 372962238888962, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (13655819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6827904 + 6827905.

It is an arithmetic number, because the mean of its divisors is an integer number (6827905).

Almost surely, 2^13655809 is an apocalyptic number.

It is an amenable number.

13655809 is a deficient number, since it is larger than the sum of its proper divisors (1).

13655809 is an equidigital number, since it uses as much as digits as its factorization.

13655809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32400, while the sum is 37.

The square root of 13655809 is about 3695.3767061018. The cubic root of 13655809 is about 239.0226981938.

It can be divided in two parts, 136 and 55809, that added together give a triangular number (55945 = T₃₃₄).

The spelling of 13655809 in words is "thirteen million, six hundred fifty-five thousand, eight hundred nine".