15990681 has 16 divisors (see below), whose sum is σ = 25426944. Its totient is φ = 8739984.

The previous prime is 15990679. The next prime is 15990701. The reversal of 15990681 is 18609951.

It is not a de Polignac number, because 15990681 - 2¹ = 15990679 is a prime.

It is a super-2 number, since 2×15990681² = 511403757687522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (15990641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16071 + ... + 17036.

It is an arithmetic number, because the mean of its divisors is an integer number (1589184).

Almost surely, 2^15990681 is an apocalyptic number.

It is an amenable number.

15990681 is a deficient number, since it is larger than the sum of its proper divisors (9436263).

15990681 is a wasteful number, since it uses less digits than its factorization.

15990681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33140.

The product of its (nonzero) digits is 19440, while the sum is 39.

The square root of 15990681 is about 3998.8349553339. The cubic root of 15990681 is about 251.9352787935.

The spelling of 15990681 in words is "fifteen million, nine hundred ninety thousand, six hundred eighty-one".