77215993 has 2 divisors, whose sum is σ = 77215994. Its totient is φ = 77215992.

The previous prime is 77215987. The next prime is 77216017. The reversal of 77215993 is 39951277.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77211369 + 4624 = 8787^2 + 68^2 .

It is a cyclic number.

It is not a de Polignac number, because 77215993 - 2⁵ = 77215961 is a prime.

It is not a weakly prime, because it can be changed into another prime (77215903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38607996 + 38607997.

It is an arithmetic number, because the mean of its divisors is an integer number (38607997).

Almost surely, 2^77215993 is an apocalyptic number.

It is an amenable number.

77215993 is a deficient number, since it is larger than the sum of its proper divisors (1).

77215993 is an equidigital number, since it uses as much as digits as its factorization.

77215993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 119070, while the sum is 43.

The square root of 77215993 is about 8787.2631120275. The cubic root of 77215993 is about 425.8295088736.

The spelling of 77215993 in words is "seventy-seven million, two hundred fifteen thousand, nine hundred ninety-three".