78997577 has 2 divisors, whose sum is σ = 78997578. Its totient is φ = 78997576.

The previous prime is 78997561. The next prime is 78997603. The reversal of 78997577 is 77579987.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69822736 + 9174841 = 8356^2 + 3029^2 .

It is a cyclic number.

It is not a de Polignac number, because 78997577 - 2⁴ = 78997561 is a prime.

It is not a weakly prime, because it can be changed into another prime (78997277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39498788 + 39498789.

It is an arithmetic number, because the mean of its divisors is an integer number (39498789).

Almost surely, 2^78997577 is an apocalyptic number.

It is an amenable number.

78997577 is a deficient number, since it is larger than the sum of its proper divisors (1).

78997577 is an equidigital number, since it uses as much as digits as its factorization.

78997577 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7779240, while the sum is 59.

The square root of 78997577 is about 8888.0581118712. The cubic root of 78997577 is about 429.0796558618.

The spelling of 78997577 in words is "seventy-eight million, nine hundred ninety-seven thousand, five hundred seventy-seven".