78996557 has 2 divisors, whose sum is σ = 78996558. Its totient is φ = 78996556.

The previous prime is 78996539. The next prime is 78996601. The reversal of 78996557 is 75569987.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62504836 + 16491721 = 7906^2 + 4061^2 .

It is a cyclic number.

It is not a de Polignac number, because 78996557 - 2⁸ = 78996301 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78996257) 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, 39498278 + 39498279.

It is an arithmetic number, because the mean of its divisors is an integer number (39498279).

Almost surely, 2^78996557 is an apocalyptic number.

It is an amenable number.

78996557 is a deficient number, since it is larger than the sum of its proper divisors (1).

78996557 is an equidigital number, since it uses as much as digits as its factorization.

78996557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4762800, while the sum is 56.

The square root of 78996557 is about 8888.0007313231. Note that the first 3 decimals coincide. The cubic root of 78996557 is about 429.0778091253.

The spelling of 78996557 in words is "seventy-eight million, nine hundred ninety-six thousand, five hundred fifty-seven".