31178958649 has 2 divisors, whose sum is σ = 31178958650. Its totient is φ = 31178958648.

The previous prime is 31178958607. The next prime is 31178958739. The reversal of 31178958649 is 94685987113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21758315049 + 9420643600 = 147507^2 + 97060^2 .

It is an emirp because it is prime and its reverse (94685987113) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31178958649 is a prime.

It is not a weakly prime, because it can be changed into another prime (31178958049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15589479324 + 15589479325.

It is an arithmetic number, because the mean of its divisors is an integer number (15589479325).

Almost surely, 2^31178958649 is an apocalyptic number.

It is an amenable number.

31178958649 is a deficient number, since it is larger than the sum of its proper divisors (1).

31178958649 is an equidigital number, since it uses as much as digits as its factorization.

31178958649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13063680, while the sum is 61.

The spelling of 31178958649 in words is "thirty-one billion, one hundred seventy-eight million, nine hundred fifty-eight thousand, six hundred forty-nine".