15991472731 has 12 divisors (see below), whose sum is σ = 17475094560. Its totient is φ = 14625917280.

The previous prime is 15991472719. The next prime is 15991472767. The reversal of 15991472731 is 13727419951.

15991472731 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 15991472731 - 2⁹ = 15991472219 is a prime.

It is a super-2 number, since 2×15991472731² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15991472711) 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 11 ways as a sum of consecutive naturals, for example, 415635 + ... + 452476.

It is an arithmetic number, because the mean of its divisors is an integer number (1456257880).

Almost surely, 2^15991472731 is an apocalyptic number.

15991472731 is a deficient number, since it is larger than the sum of its proper divisors (1483621829).

15991472731 is a wasteful number, since it uses less digits than its factorization.

15991472731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 868246 (or 868233 counting only the distinct ones).

The product of its digits is 476280, while the sum is 49.

The spelling of 15991472731 in words is "fifteen billion, nine hundred ninety-one million, four hundred seventy-two thousand, seven hundred thirty-one".