77215973 has 2 divisors, whose sum is σ = 77215974. Its totient is φ = 77215972.

The previous prime is 77215961. The next prime is 77215987. The reversal of 77215973 is 37951277.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68442529 + 8773444 = 8273^2 + 2962^2 .

It is a cyclic number.

It is not a de Polignac number, because 77215973 - 2⁶ = 77215909 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 77215973.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77215903) 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, 38607986 + 38607987.

It is an arithmetic number, because the mean of its divisors is an integer number (38607987).

Almost surely, 2^77215973 is an apocalyptic number.

It is an amenable number.

77215973 is a deficient number, since it is larger than the sum of its proper divisors (1).

77215973 is an equidigital number, since it uses as much as digits as its factorization.

77215973 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 92610, while the sum is 41.

The square root of 77215973 is about 8787.2619740167. The cubic root of 77215973 is about 425.8294721084.

The spelling of 77215973 in words is "seventy-seven million, two hundred fifteen thousand, nine hundred seventy-three".