79778091945 has 32 divisors (see below), whose sum is σ = 128012931072. Its totient is φ = 42425836992.

The previous prime is 79778091931. The next prime is 79778091971. The reversal of 79778091945 is 54919087797.

It is a happy number.

It is not a de Polignac number, because 79778091945 - 2⁷ = 79778091817 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8034754 + ... + 8044676.

It is an arithmetic number, because the mean of its divisors is an integer number (4000404096).

Almost surely, 2^79778091945 is an apocalyptic number.

It is an amenable number.

79778091945 is a deficient number, since it is larger than the sum of its proper divisors (48234839127).

79778091945 is a wasteful number, since it uses less digits than its factorization.

79778091945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11421.

The product of its (nonzero) digits is 40007520, while the sum is 66.

The spelling of 79778091945 in words is "seventy-nine billion, seven hundred seventy-eight million, ninety-one thousand, nine hundred forty-five".