77920057 has 2 divisors, whose sum is σ = 77920058. Its totient is φ = 77920056.

The previous prime is 77920043. The next prime is 77920079. The reversal of 77920057 is 75002977.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 73547776 + 4372281 = 8576^2 + 2091^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77920057 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 77919998 and 77920025.

It is not a weakly prime, because it can be changed into another prime (77920097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38960028 + 38960029.

It is an arithmetic number, because the mean of its divisors is an integer number (38960029).

Almost surely, 2^77920057 is an apocalyptic number.

It is an amenable number.

77920057 is a deficient number, since it is larger than the sum of its proper divisors (1).

77920057 is an equidigital number, since it uses as much as digits as its factorization.

77920057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30870, while the sum is 37.

The square root of 77920057 is about 8827.2338249307. The cubic root of 77920057 is about 427.1198485493.

The spelling of 77920057 in words is "seventy-seven million, nine hundred twenty thousand, fifty-seven".