78757538778 has 12 divisors (see below), whose sum is σ = 170641334058. Its totient is φ = 26252512920.

The previous prime is 78757538737. The next prime is 78757538857. The reversal of 78757538778 is 87783575787.

It is a happy number.

78757538778 is a `hidden beast` number, since 7 + 87 + 5 + 7 + 538 + 7 + 7 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 69425399169 + 9332139609 = 263487^2 + 96603^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2187709393 + ... + 2187709428.

Almost surely, 2^78757538778 is an apocalyptic number.

78757538778 is an abundant number, since it is smaller than the sum of its proper divisors (91883795280).

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

78757538778 is a wasteful number, since it uses less digits than its factorization.

78757538778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4375418829 (or 4375418826 counting only the distinct ones).

The product of its digits is 645388800, while the sum is 72.

The spelling of 78757538778 in words is "seventy-eight billion, seven hundred fifty-seven million, five hundred thirty-eight thousand, seven hundred seventy-eight".