15964991 has 8 divisors (see below), whose sum is σ = 18282624. Its totient is φ = 13656600.

The previous prime is 15964957. The next prime is 15964999. The reversal of 15964991 is 19946951.

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

It is a cyclic number.

It is not a de Polignac number, because 15964991 - 2¹⁰ = 15963967 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15964999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1916 + ... + 5966.

It is an arithmetic number, because the mean of its divisors is an integer number (2285328).

Almost surely, 2^15964991 is an apocalyptic number.

15964991 is a deficient number, since it is larger than the sum of its proper divisors (2317633).

15964991 is an equidigital number, since it uses as much as digits as its factorization.

15964991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4621.

The product of its digits is 87480, while the sum is 44.

The square root of 15964991 is about 3995.6214785688. The cubic root of 15964991 is about 251.8002900374.

The spelling of 15964991 in words is "fifteen million, nine hundred sixty-four thousand, nine hundred ninety-one".