15917381640 has 96 divisors (see below), whose sum is σ = 51999756120. Its totient is φ = 4222623744.

The previous prime is 15917381621. The next prime is 15917381659. The reversal of 15917381640 is 4618371951.

15917381640 is a `hidden beast` number, since 1 + 591 + 7 + 3 + 8 + 16 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (15917381621) and next prime (15917381659).

It can be written as a sum of positive squares in 4 ways, for example, as 10523066724 + 5394314916 = 102582^2 + 73446^2 .

It is a super-3 number, since 3×15917381640³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 45067 + ... + 184026.

Almost surely, 2^15917381640 is an apocalyptic number.

15917381640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15917381640 is an abundant number, since it is smaller than the sum of its proper divisors (36082374480).

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

15917381640 is a wasteful number, since it uses less digits than its factorization.

15917381640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229303 (or 229296 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The spelling of 15917381640 in words is "fifteen billion, nine hundred seventeen million, three hundred eighty-one thousand, six hundred forty".