13664257 has 2 divisors, whose sum is σ = 13664258. Its totient is φ = 13664256.

The previous prime is 13664251. The next prime is 13664279. The reversal of 13664257 is 75246631.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7268416 + 6395841 = 2696^2 + 2529^2 .

It is a cyclic number.

It is not a de Polignac number, because 13664257 - 2⁷ = 13664129 is a prime.

It is not a weakly prime, because it can be changed into another prime (13664251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6832128 + 6832129.

It is an arithmetic number, because the mean of its divisors is an integer number (6832129).

It is a Proth number, since it is equal to 417 ⋅ 2¹⁵ + 1 and 417 < 2¹⁵.

Almost surely, 2^13664257 is an apocalyptic number.

It is an amenable number.

13664257 is a deficient number, since it is larger than the sum of its proper divisors (1).

13664257 is an equidigital number, since it uses as much as digits as its factorization.

13664257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 34.

The square root of 13664257 is about 3696.5195792799. The cubic root of 13664257 is about 239.0719775273.

The spelling of 13664257 in words is "thirteen million, six hundred sixty-four thousand, two hundred fifty-seven".