78625427778 has 12 divisors (see below), whose sum is σ = 170355093558. Its totient is φ = 26208475920.

The previous prime is 78625427753. The next prime is 78625427791. The reversal of 78625427778 is 87772452687.

It is a happy number.

78625427778 is a `hidden beast` number, since 7 + 86 + 2 + 542 + 7 + 7 + 7 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 78564165849 + 61261929 = 280293^2 + 7827^2 .

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, 2184039643 + ... + 2184039678.

Almost surely, 2^78625427778 is an apocalyptic number.

78625427778 is an abundant number, since it is smaller than the sum of its proper divisors (91729665780).

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

78625427778 is a wasteful number, since it uses less digits than its factorization.

78625427778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4368079329 (or 4368079326 counting only the distinct ones).

The product of its digits is 73758720, while the sum is 63.

The spelling of 78625427778 in words is "seventy-eight billion, six hundred twenty-five million, four hundred twenty-seven thousand, seven hundred seventy-eight".