12515681 has 2 divisors, whose sum is σ = 12515682. Its totient is φ = 12515680.

The previous prime is 12515669. The next prime is 12515687. The reversal of 12515681 is 18651521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9333025 + 3182656 = 3055^2 + 1784^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12515681 is a prime.

It is a super-2 number, since 2×12515681² = 313284541787522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (12515687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6257840 + 6257841.

It is an arithmetic number, because the mean of its divisors is an integer number (6257841).

Almost surely, 2^12515681 is an apocalyptic number.

It is an amenable number.

12515681 is a deficient number, since it is larger than the sum of its proper divisors (1).

12515681 is an equidigital number, since it uses as much as digits as its factorization.

12515681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2400, while the sum is 29.

The square root of 12515681 is about 3537.7508391632. The cubic root of 12515681 is about 232.1764474673.

The spelling of 12515681 in words is "twelve million, five hundred fifteen thousand, six hundred eighty-one".