77712979 has 4 divisors (see below), whose sum is σ = 78807600. Its totient is φ = 76618360.

The previous prime is 77712977. The next prime is 77712989. The reversal of 77712979 is 97921777.

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 77712979 - 2¹ = 77712977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77712977) 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, 547204 + ... + 547345.

It is an arithmetic number, because the mean of its divisors is an integer number (19701900).

Almost surely, 2^77712979 is an apocalyptic number.

77712979 is a deficient number, since it is larger than the sum of its proper divisors (1094621).

77712979 is a wasteful number, since it uses less digits than its factorization.

77712979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1094620.

The product of its digits is 388962, while the sum is 49.

The square root of 77712979 is about 8815.4965260046. The cubic root of 77712979 is about 426.7411459201.

The spelling of 77712979 in words is "seventy-seven million, seven hundred twelve thousand, nine hundred seventy-nine".