15963891 has 16 divisors (see below), whose sum is σ = 22131360. Its totient is φ = 10223360.

The previous prime is 15963887. The next prime is 15963907. The reversal of 15963891 is 19836951.

It is a cyclic number.

It is not a de Polignac number, because 15963891 - 2² = 15963887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (15963821) 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, 24121 + ... + 24773.

It is an arithmetic number, because the mean of its divisors is an integer number (1383210).

Almost surely, 2^15963891 is an apocalyptic number.

15963891 is a deficient number, since it is larger than the sum of its proper divisors (6167469).

15963891 is a wasteful number, since it uses less digits than its factorization.

15963891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 966.

The product of its digits is 58320, while the sum is 42.

The square root of 15963891 is about 3995.4838255210. The cubic root of 15963891 is about 251.7945068275.

The spelling of 15963891 in words is "fifteen million, nine hundred sixty-three thousand, eight hundred ninety-one".