77931031 has 2 divisors, whose sum is σ = 77931032. Its totient is φ = 77931030.

The previous prime is 77931017. The next prime is 77931047. The reversal of 77931031 is 13013977.

It is a weak prime.

It is an emirp because it is prime and its reverse (13013977) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77931031 - 2⁵ = 77930999 is a prime.

It is a super-2 number, since 2×77931031² = 12146491185445922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 77930984 and 77931002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77931011) 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, 38965515 + 38965516.

It is an arithmetic number, because the mean of its divisors is an integer number (38965516).

Almost surely, 2^77931031 is an apocalyptic number.

77931031 is a deficient number, since it is larger than the sum of its proper divisors (1).

77931031 is an equidigital number, since it uses as much as digits as its factorization.

77931031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3969, while the sum is 31.

The square root of 77931031 is about 8827.8554020781. The cubic root of 77931031 is about 427.1398989846.

The spelling of 77931031 in words is "seventy-seven million, nine hundred thirty-one thousand, thirty-one".