78750390625 has 27 divisors (see below), whose sum is σ = 98657664331. Its totient is φ = 62860000000.

The previous prime is 78750390577. The next prime is 78750390629. The reversal of 78750390625 is 52609305787.

The square root of 78750390625 is 280625.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 13 ways, for example, as 8262264609 + 70488126016 = 90897^2 + 265496^2 .

It is a de Polignac number, because none of the positive numbers 2^k-78750390625 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78750390629) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 175390401 + ... + 175390849.

Almost surely, 2^78750390625 is an apocalyptic number.

78750390625 is the 280625-th square number.

78750390625 is the 140313-rd centered octagonal number.

It is an amenable number.

78750390625 is a deficient number, since it is larger than the sum of its proper divisors (19907273706).

78750390625 is an frugal number, since it uses more digits than its factorization.

78750390625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 938 (or 454 counting only the distinct ones).

The product of its (nonzero) digits is 3175200, while the sum is 52.

The spelling of 78750390625 in words is "seventy-eight billion, seven hundred fifty million, three hundred ninety thousand, six hundred twenty-five".