79977779 has 4 divisors (see below), whose sum is σ = 91403184. Its totient is φ = 68552376.

The previous prime is 79977773. The next prime is 79977817. The reversal of 79977779 is 97777997.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-79977779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79977773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5712692 + ... + 5712705.

It is an arithmetic number, because the mean of its divisors is an integer number (22850796).

Almost surely, 2^79977779 is an apocalyptic number.

79977779 is a deficient number, since it is larger than the sum of its proper divisors (11425405).

79977779 is a wasteful number, since it uses less digits than its factorization.

79977779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11425404.

The product of its digits is 12252303, while the sum is 62.

The square root of 79977779 is about 8943.0296320654. The cubic root of 79977779 is about 430.8470395677.

The spelling of 79977779 in words is "seventy-nine million, nine hundred seventy-seven thousand, seven hundred seventy-nine".