78456775646 has 16 divisors (see below), whose sum is σ = 118617609600. Its totient is φ = 38918709720.

The previous prime is 78456775619. The next prime is 78456775651. The reversal of 78456775646 is 64657765487.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 145940 + ... + 422151.

It is an arithmetic number, because the mean of its divisors is an integer number (7413600600).

Almost surely, 2^78456775646 is an apocalyptic number.

78456775646 is a deficient number, since it is larger than the sum of its proper divisors (40160833954).

78456775646 is a wasteful number, since it uses less digits than its factorization.

78456775646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 568639.

The product of its digits is 237081600, while the sum is 65.

The spelling of 78456775646 in words is "seventy-eight billion, four hundred fifty-six million, seven hundred seventy-five thousand, six hundred forty-six".