78258881664 has 48 divisors (see below), whose sum is σ = 225198087270. Its totient is φ = 26086293504.

The previous prime is 78258881641. The next prime is 78258881689. The reversal of 78258881664 is 46618885287.

It can be written as a sum of positive squares in only one way, i.e., 47353241664 + 30905640000 = 217608^2 + 175800^2 .

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

It is a super-2 number, since 2×78258881664² (a number of 23 digits) contains 22 as substring.

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, 33965377 + ... + 33967680.

Almost surely, 2^78258881664 is an apocalyptic number.

It is an amenable number.

78258881664 is an abundant number, since it is smaller than the sum of its proper divisors (146939205606).

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

78258881664 is a wasteful number, since it uses less digits than its factorization.

78258881664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67933077 (or 67933062 counting only the distinct ones).

The product of its digits is 41287680, while the sum is 63.

The spelling of 78258881664 in words is "seventy-eight billion, two hundred fifty-eight million, eight hundred eighty-one thousand, six hundred sixty-four".