77799913 has 2 divisors, whose sum is σ = 77799914. Its totient is φ = 77799912.

The previous prime is 77799901. The next prime is 77799923. The reversal of 77799913 is 31999777.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76947984 + 851929 = 8772^2 + 923^2 .

It is an emirp because it is prime and its reverse (31999777) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77799913 - 2⁹ = 77799401 is a prime.

It is not a weakly prime, because it can be changed into another prime (77799923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38899956 + 38899957.

It is an arithmetic number, because the mean of its divisors is an integer number (38899957).

Almost surely, 2^77799913 is an apocalyptic number.

It is an amenable number.

77799913 is a deficient number, since it is larger than the sum of its proper divisors (1).

77799913 is an equidigital number, since it uses as much as digits as its factorization.

77799913 is an evil number, because the sum of its binary digits is even.

The product of its digits is 750141, while the sum is 52.

The square root of 77799913 is about 8820.4258967467. The cubic root of 77799913 is about 426.9002119707.

The spelling of 77799913 in words is "seventy-seven million, seven hundred ninety-nine thousand, nine hundred thirteen".