77979449 has 2 divisors, whose sum is σ = 77979450. Its totient is φ = 77979448.

The previous prime is 77979431. The next prime is 77979487. The reversal of 77979449 is 94497977.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60171049 + 17808400 = 7757^2 + 4220^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77979449 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 77979394 and 77979403.

It is not a weakly prime, because it can be changed into another prime (77979749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38989724 + 38989725.

It is an arithmetic number, because the mean of its divisors is an integer number (38989725).

Almost surely, 2^77979449 is an apocalyptic number.

It is an amenable number.

77979449 is a deficient number, since it is larger than the sum of its proper divisors (1).

77979449 is an equidigital number, since it uses as much as digits as its factorization.

77979449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4000752, while the sum is 56.

The square root of 77979449 is about 8830.5973184151. The cubic root of 77979449 is about 427.2283403401.

The spelling of 77979449 in words is "seventy-seven million, nine hundred seventy-nine thousand, four hundred forty-nine".