77956399 has 2 divisors, whose sum is σ = 77956400. Its totient is φ = 77956398.

The previous prime is 77956391. The next prime is 77956421. The reversal of 77956399 is 99365977.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 77956399 - 2³ = 77956391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77956391) 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 as a sum of consecutive naturals, namely, 38978199 + 38978200.

It is an arithmetic number, because the mean of its divisors is an integer number (38978200).

Almost surely, 2^77956399 is an apocalyptic number.

77956399 is a deficient number, since it is larger than the sum of its proper divisors (1).

77956399 is an equidigital number, since it uses as much as digits as its factorization.

77956399 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3214890, while the sum is 55.

The square root of 77956399 is about 8829.2921007293. The cubic root of 77956399 is about 427.1862412836.

The spelling of 77956399 in words is "seventy-seven million, nine hundred fifty-six thousand, three hundred ninety-nine".