31078655681 has 2 divisors, whose sum is σ = 31078655682. Its totient is φ = 31078655680.

The previous prime is 31078655669. The next prime is 31078655771. The reversal of 31078655681 is 18655687013.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18766534081 + 12312121600 = 136991^2 + 110960^2 .

It is a cyclic number.

It is not a de Polignac number, because 31078655681 - 2⁶ = 31078655617 is a prime.

It is a super-2 number, since 2×31078655681² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31078655611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15539327840 + 15539327841.

It is an arithmetic number, because the mean of its divisors is an integer number (15539327841).

Almost surely, 2^31078655681 is an apocalyptic number.

It is an amenable number.

31078655681 is a deficient number, since it is larger than the sum of its proper divisors (1).

31078655681 is an equidigital number, since it uses as much as digits as its factorization.

31078655681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1209600, while the sum is 50.

The spelling of 31078655681 in words is "thirty-one billion, seventy-eight million, six hundred fifty-five thousand, six hundred eighty-one".