78664715525457 has 6 divisors (see below), whose sum is σ = 113626811314562. Its totient is φ = 52443143683632.

The previous prime is 78664715525447. The next prime is 78664715525537. The reversal of 78664715525457 is 75452551746687.

78664715525457 is a `hidden beast` number, since 7 + 8 + 6 + 6 + 4 + 71 + 5 + 5 + 2 + 545 + 7 = 666.

It can be written as a sum of positive squares in only one way, i.e., 76462590115521 + 2202125409936 = 8744289^2 + 1483956^2 .

It is not a de Polignac number, because 78664715525457 - 2¹¹ = 78664715523409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78664715525447) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4370261973628 + ... + 4370261973645.

Almost surely, 2^{78664715525457} is an apocalyptic number.

It is an amenable number.

78664715525457 is a deficient number, since it is larger than the sum of its proper divisors (34962095789105).

78664715525457 is a wasteful number, since it uses less digits than its factorization.

78664715525457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8740523947279 (or 8740523947276 counting only the distinct ones).

The product of its digits is 1975680000, while the sum is 72.

The spelling of 78664715525457 in words is "seventy-eight trillion, six hundred sixty-four billion, seven hundred fifteen million, five hundred twenty-five thousand, four hundred fifty-seven".