77966779 has 4 divisors (see below), whose sum is σ = 85054680. Its totient is φ = 70878880.

The previous prime is 77966737. The next prime is 77966809. The reversal of 77966779 is 97766977.

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

It is a cyclic number.

It is not a de Polignac number, because 77966779 - 2¹⁵ = 77934011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77966729) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3543934 + ... + 3543955.

It is an arithmetic number, because the mean of its divisors is an integer number (21263670).

Almost surely, 2^77966779 is an apocalyptic number.

77966779 is a deficient number, since it is larger than the sum of its proper divisors (7087901).

77966779 is a wasteful number, since it uses less digits than its factorization.

77966779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7087900.

The product of its digits is 7001316, while the sum is 58.

The square root of 77966779 is about 8829.8798972579. The cubic root of 77966779 is about 427.2052005842.

The spelling of 77966779 in words is "seventy-seven million, nine hundred sixty-six thousand, seven hundred seventy-nine".