77988431 has 2 divisors, whose sum is σ = 77988432. Its totient is φ = 77988430.

The previous prime is 77988413. The next prime is 77988451. The reversal of 77988431 is 13488977.

Together with previous prime (77988413) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77988431 is a prime.

It is a super-2 number, since 2×77988431² = 12164390739683522, 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 (77988451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38994215 + 38994216.

It is an arithmetic number, because the mean of its divisors is an integer number (38994216).

Almost surely, 2^77988431 is an apocalyptic number.

77988431 is a deficient number, since it is larger than the sum of its proper divisors (1).

77988431 is an equidigital number, since it uses as much as digits as its factorization.

77988431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 338688, while the sum is 47.

The square root of 77988431 is about 8831.1058763894. The cubic root of 77988431 is about 427.2447430278.

The spelling of 77988431 in words is "seventy-seven million, nine hundred eighty-eight thousand, four hundred thirty-one".