78638868864 has 48 divisors (see below), whose sum is σ = 226291540020. Its totient is φ = 26212955904.

The previous prime is 78638868851. The next prime is 78638868883. The reversal of 78638868864 is 46886883687.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 78638868792 and 78638868801.

It is a congruent 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, 34130302 + ... + 34132605.

Almost surely, 2^78638868864 is an apocalyptic number.

It is an amenable number.

78638868864 is an abundant number, since it is smaller than the sum of its proper divisors (147652671156).

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

78638868864 is a wasteful number, since it uses less digits than its factorization.

78638868864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68262927 (or 68262912 counting only the distinct ones).

The product of its digits is 594542592, while the sum is 72.

The spelling of 78638868864 in words is "seventy-eight billion, six hundred thirty-eight million, eight hundred sixty-eight thousand, eight hundred sixty-four".