77309989 has 2 divisors, whose sum is σ = 77309990. Its totient is φ = 77309988.

The previous prime is 77309977. The next prime is 77310007. The reversal of 77309989 is 98990377.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49589764 + 27720225 = 7042^2 + 5265^2 .

It is a cyclic number.

It is not a de Polignac number, because 77309989 - 2⁵ = 77309957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77301989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38654994 + 38654995.

It is an arithmetic number, because the mean of its divisors is an integer number (38654995).

Almost surely, 2^77309989 is an apocalyptic number.

It is an amenable number.

77309989 is a deficient number, since it is larger than the sum of its proper divisors (1).

77309989 is an equidigital number, since it uses as much as digits as its factorization.

77309989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 857304, while the sum is 52.

The square root of 77309989 is about 8792.6099083264. The cubic root of 77309989 is about 426.0022280148.

The spelling of 77309989 in words is "seventy-seven million, three hundred nine thousand, nine hundred eighty-nine".