78332557 has 2 divisors, whose sum is σ = 78332558. Its totient is φ = 78332556.

The previous prime is 78332533. The next prime is 78332561. The reversal of 78332557 is 75523387.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77898276 + 434281 = 8826^2 + 659^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78332557 is a prime.

It is a super-2 number, since 2×78332557² = 12271978972316498, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78335557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39166278 + 39166279.

It is an arithmetic number, because the mean of its divisors is an integer number (39166279).

Almost surely, 2^78332557 is an apocalyptic number.

It is an amenable number.

78332557 is a deficient number, since it is larger than the sum of its proper divisors (1).

78332557 is an equidigital number, since it uses as much as digits as its factorization.

78332557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 176400, while the sum is 40.

The square root of 78332557 is about 8850.5681738519. The cubic root of 78332557 is about 427.8722305455.

The spelling of 78332557 in words is "seventy-eight million, three hundred thirty-two thousand, five hundred fifty-seven".