15681091 has 2 divisors, whose sum is σ = 15681092. Its totient is φ = 15681090.

The previous prime is 15681053. The next prime is 15681097. The reversal of 15681091 is 19018651.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15681091 is a prime.

It is a super-2 number, since 2×15681091² = 491793229900562, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (15681097) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7840545 + 7840546.

It is an arithmetic number, because the mean of its divisors is an integer number (7840546).

Almost surely, 2^15681091 is an apocalyptic number.

15681091 is a deficient number, since it is larger than the sum of its proper divisors (1).

15681091 is an equidigital number, since it uses as much as digits as its factorization.

15681091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 31.

The square root of 15681091 is about 3959.9357318017. The cubic root of 15681091 is about 250.2987947445.

The spelling of 15681091 in words is "fifteen million, six hundred eighty-one thousand, ninety-one".