78735256957 has 4 divisors (see below), whose sum is σ = 89983150816. Its totient is φ = 67487363100.

The previous prime is 78735256949. The next prime is 78735256991. The reversal of 78735256957 is 75965253787.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75965253787 = 43 ⋅1766633809.

It is a cyclic number.

It is not a de Polignac number, because 78735256957 - 2³ = 78735256949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78735256927) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5623946919 + ... + 5623946932.

It is an arithmetic number, because the mean of its divisors is an integer number (22495787704).

Almost surely, 2^78735256957 is an apocalyptic number.

It is an amenable number.

78735256957 is a deficient number, since it is larger than the sum of its proper divisors (11247893859).

78735256957 is a wasteful number, since it uses less digits than its factorization.

78735256957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11247893858.

The product of its digits is 111132000, while the sum is 64.

The spelling of 78735256957 in words is "seventy-eight billion, seven hundred thirty-five million, two hundred fifty-six thousand, nine hundred fifty-seven".