78887806531 has 4 divisors (see below), whose sum is σ = 79187760432. Its totient is φ = 78587852632.

The previous prime is 78887806511. The next prime is 78887806549. The reversal of 78887806531 is 13560878887.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 78887806531 - 2²³ = 78879417923 is a prime.

It is a super-2 number, since 2×78887806531² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78887806531.

It is not an unprimeable number, because it can be changed into a prime (78887806511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 149976556 + ... + 149977081.

It is an arithmetic number, because the mean of its divisors is an integer number (19796940108).

Almost surely, 2^78887806531 is an apocalyptic number.

78887806531 is a deficient number, since it is larger than the sum of its proper divisors (299953901).

78887806531 is a wasteful number, since it uses less digits than its factorization.

78887806531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299953900.

The product of its (nonzero) digits is 18063360, while the sum is 61.

The spelling of 78887806531 in words is "seventy-eight billion, eight hundred eighty-seven million, eight hundred six thousand, five hundred thirty-one".