79309921786 has 4 divisors (see below), whose sum is σ = 118964882682. Its totient is φ = 39654960892.

The previous prime is 79309921777. The next prime is 79309921883. The reversal of 79309921786 is 68712990397.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 62165947561 + 17143974225 = 249331^2 + 130935^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19827480445 + ... + 19827480448.

Almost surely, 2^79309921786 is an apocalyptic number.

79309921786 is a deficient number, since it is larger than the sum of its proper divisors (39654960896).

79309921786 is a wasteful number, since it uses less digits than its factorization.

79309921786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39654960895.

The product of its (nonzero) digits is 10287648, while the sum is 61.

The spelling of 79309921786 in words is "seventy-nine billion, three hundred nine million, nine hundred twenty-one thousand, seven hundred eighty-six".