15491791 has 12 divisors (see below), whose sum is σ = 18086328. Its totient is φ = 13230672.

The previous prime is 15491767. The next prime is 15491797. The reversal of 15491791 is 19719451.

It is not a de Polignac number, because 15491791 - 2⁵ = 15491759 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 15491791.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15491797) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22545 + ... + 23221.

It is an arithmetic number, because the mean of its divisors is an integer number (1507194).

Almost surely, 2^15491791 is an apocalyptic number.

15491791 is a deficient number, since it is larger than the sum of its proper divisors (2594537).

15491791 is an equidigital number, since it uses as much as digits as its factorization.

15491791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1158 (or 1151 counting only the distinct ones).

The product of its digits is 11340, while the sum is 37.

The square root of 15491791 is about 3935.9612548906. The cubic root of 15491791 is about 249.2875234375.

The spelling of 15491791 in words is "fifteen million, four hundred ninety-one thousand, seven hundred ninety-one".