11656681 has 2 divisors, whose sum is σ = 11656682. Its totient is φ = 11656680.

The previous prime is 11656663. The next prime is 11656721. The reversal of 11656681 is 18665611.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6553600 + 5103081 = 2560^2 + 2259^2 .

It is a cyclic number.

It is not a de Polignac number, because 11656681 - 2⁵ = 11656649 is a prime.

It is a super-2 number, since 2×11656681² = 271756423871522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (11656081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5828340 + 5828341.

It is an arithmetic number, because the mean of its divisors is an integer number (5828341).

Almost surely, 2^11656681 is an apocalyptic number.

It is an amenable number.

11656681 is a deficient number, since it is larger than the sum of its proper divisors (1).

11656681 is an equidigital number, since it uses as much as digits as its factorization.

11656681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8640, while the sum is 34.

The square root of 11656681 is about 3414.1881904781. The cubic root of 11656681 is about 226.7383440655.

The spelling of 11656681 in words is "eleven million, six hundred fifty-six thousand, six hundred eighty-one".