77945579 has 2 divisors, whose sum is σ = 77945580. Its totient is φ = 77945578.

The previous prime is 77945521. The next prime is 77945641. The reversal of 77945579 is 97554977.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77945579 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 77945579.

It is not a weakly prime, because it can be changed into another prime (77945279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38972789 + 38972790.

It is an arithmetic number, because the mean of its divisors is an integer number (38972790).

Almost surely, 2^77945579 is an apocalyptic number.

77945579 is a deficient number, since it is larger than the sum of its proper divisors (1).

77945579 is an equidigital number, since it uses as much as digits as its factorization.

77945579 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2778300, while the sum is 53.

The square root of 77945579 is about 8828.6793463122. The cubic root of 77945579 is about 427.1664765217.

The spelling of 77945579 in words is "seventy-seven million, nine hundred forty-five thousand, five hundred seventy-nine".