78888398666 has 16 divisors (see below), whose sum is σ = 147531551040. Its totient is φ = 30735739680.

The previous prime is 78888398647. The next prime is 78888398723. The reversal of 78888398666 is 66689388887.

It is a Harshad number since it is a multiple of its sum of digits (77).

It is a Curzon 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, 256131011 + ... + 256131318.

It is an arithmetic number, because the mean of its divisors is an integer number (9220721940).

Almost surely, 2^78888398666 is an apocalyptic number.

78888398666 is a deficient number, since it is larger than the sum of its proper divisors (68643152374).

78888398666 is a wasteful number, since it uses less digits than its factorization.

78888398666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 512262349.

The product of its digits is 1337720832, while the sum is 77.

The spelling of 78888398666 in words is "seventy-eight billion, eight hundred eighty-eight million, three hundred ninety-eight thousand, six hundred sixty-six".