78316987491 has 12 divisors (see below), whose sum is σ = 113950265832. Its totient is φ = 51830219616.

The previous prime is 78316987459. The next prime is 78316987561. The reversal of 78316987491 is 19478961387.

78316987491 is a `hidden beast` number, since 7 + 8 + 3 + 1 + 69 + 87 + 491 = 666.

It is not a de Polignac number, because 78316987491 - 2⁵ = 78316987459 is a prime.

It is a super-2 number, since 2×78316987491² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78316987451) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31757481 + ... + 31759946.

It is an arithmetic number, because the mean of its divisors is an integer number (9495855486).

Almost surely, 2^78316987491 is an apocalyptic number.

78316987491 is a deficient number, since it is larger than the sum of its proper divisors (35633278341).

78316987491 is a wasteful number, since it uses less digits than its factorization.

78316987491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63517570 (or 63517567 counting only the distinct ones).

The product of its digits is 18289152, while the sum is 63.

The spelling of 78316987491 in words is "seventy-eight billion, three hundred sixteen million, nine hundred eighty-seven thousand, four hundred ninety-one".