15991494 has 8 divisors (see below), whose sum is σ = 31983000. Its totient is φ = 5330496.

The previous prime is 15991477. The next prime is 15991501. The reversal of 15991494 is 49419951.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

15991494 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1332619 + ... + 1332630.

It is an arithmetic number, because the mean of its divisors is an integer number (3997875).

Almost surely, 2^15991494 is an apocalyptic number.

15991494 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

15991494 is a wasteful number, since it uses less digits than its factorization.

15991494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2665254.

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

The square root of 15991494 is about 3998.9366086499. The cubic root of 15991494 is about 251.9395483618.

The spelling of 15991494 in words is "fifteen million, nine hundred ninety-one thousand, four hundred ninety-four".