15991495938 has 24 divisors (see below), whose sum is σ = 37798081776. Its totient is φ = 4845907800.

The previous prime is 15991495909. The next prime is 15991495969. The reversal of 15991495938 is 83959419951.

15991495938 is a `hidden beast` number, since 1 + 59 + 9 + 1 + 495 + 93 + 8 = 666.

15991495938 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is an unprimeable number.

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, 40382368 + ... + 40382763.

It is an arithmetic number, because the mean of its divisors is an integer number (1574920074).

Almost surely, 2^15991495938 is an apocalyptic number.

15991495938 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

15991495938 is an abundant number, since it is smaller than the sum of its proper divisors (21806585838).

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

15991495938 is a wasteful number, since it uses less digits than its factorization.

15991495938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80765150 (or 80765147 counting only the distinct ones).

The product of its digits is 15746400, while the sum is 63.

The spelling of 15991495938 in words is "fifteen billion, nine hundred ninety-one million, four hundred ninety-five thousand, nine hundred thirty-eight".