31816147997 has 2 divisors, whose sum is σ = 31816147998. Its totient is φ = 31816147996.

The previous prime is 31816147991. The next prime is 31816148069. The reversal of 31816147997 is 79974161813.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31505895001 + 310252996 = 177499^2 + 17614^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31816147997 is a prime.

It is a super-2 number, since 2×31816147997² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31816147991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15908073998 + 15908073999.

It is an arithmetic number, because the mean of its divisors is an integer number (15908073999).

Almost surely, 2^31816147997 is an apocalyptic number.

It is an amenable number.

31816147997 is a deficient number, since it is larger than the sum of its proper divisors (1).

31816147997 is an equidigital number, since it uses as much as digits as its factorization.

31816147997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2286144, while the sum is 56.

The spelling of 31816147997 in words is "thirty-one billion, eight hundred sixteen million, one hundred forty-seven thousand, nine hundred ninety-seven".