87718665978 has 24 divisors (see below), whose sum is σ = 194692650516. Its totient is φ = 28526395200.

The previous prime is 87718665961. The next prime is 87718666003. The reversal of 87718665978 is 87956681778.

It can be written as a sum of positive squares in 2 ways, for example, as 87056272809 + 662393169 = 295053^2 + 25737^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 59429253 + ... + 59430728.

Almost surely, 2^87718665978 is an apocalyptic number.

87718665978 is an abundant number, since it is smaller than the sum of its proper divisors (106973984538).

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

87718665978 is a wasteful number, since it uses less digits than its factorization.

87718665978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118860030 (or 118860027 counting only the distinct ones).

The product of its digits is 284497920, while the sum is 72.

The spelling of 87718665978 in words is "eighty-seven billion, seven hundred eighteen million, six hundred sixty-five thousand, nine hundred seventy-eight".