79951778 has 4 divisors (see below), whose sum is σ = 119927670. Its totient is φ = 39975888.

The previous prime is 79951769. The next prime is 79951819. The reversal of 79951778 is 87715997.

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., 42289009 + 37662769 = 6503^2 + 6137^2 .

It is a super-2 number, since 2×79951778² = 12784573610722568, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19987943 + ... + 19987946.

Almost surely, 2^79951778 is an apocalyptic number.

79951778 is a deficient number, since it is larger than the sum of its proper divisors (39975892).

79951778 is a wasteful number, since it uses less digits than its factorization.

79951778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39975891.

The product of its digits is 1111320, while the sum is 53.

The square root of 79951778 is about 8941.5758119025. The cubic root of 79951778 is about 430.8003446473.

The spelling of 79951778 in words is "seventy-nine million, nine hundred fifty-one thousand, seven hundred seventy-eight".