77979 has 16 divisors (see below), whose sum is σ = 120960. Its totient is φ = 44160.

The previous prime is 77977. The next prime is 77983. The reversal of 77979 is 97977.

It is not a de Polignac number, because 77979 - 2¹ = 77977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77977) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 492 + ... + 630.

It is an arithmetic number, because the mean of its divisors is an integer number (7560).

2⁷⁷⁹⁷⁹ is an apocalyptic number.

77979 is a deficient number, since it is larger than the sum of its proper divisors (42981).

77979 is a wasteful number, since it uses less digits than its factorization.

77979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170.

The product of its digits is 27783, while the sum is 39.

The square root of 77979 is about 279.2472023136. The cubic root of 77979 is about 42.7227520355.

It can be divided in two parts, 779 and 79, that added together give a palindrome (858).

The spelling of 77979 in words is "seventy-seven thousand, nine hundred seventy-nine".