13156681 has 2 divisors, whose sum is σ = 13156682. Its totient is φ = 13156680.

The previous prime is 13156673. The next prime is 13156687. The reversal of 13156681 is 18665131.

13156681 is nontrivially palindromic in base 15.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13075456 + 81225 = 3616^2 + 285^2 .

It is a cyclic number.

It is not a de Polignac number, because 13156681 - 2³ = 13156673 is a prime.

It is a super-2 number, since 2×13156681² = 346196509871522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (13156687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6578340 + 6578341.

It is an arithmetic number, because the mean of its divisors is an integer number (6578341).

Almost surely, 2^13156681 is an apocalyptic number.

It is an amenable number.

13156681 is a deficient number, since it is larger than the sum of its proper divisors (1).

13156681 is an equidigital number, since it uses as much as digits as its factorization.

13156681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4320, while the sum is 31.

The square root of 13156681 is about 3627.2139446137. The cubic root of 13156681 is about 236.0743385942.

The spelling of 13156681 in words is "thirteen million, one hundred fifty-six thousand, six hundred eighty-one".