31997182817 has 2 divisors, whose sum is σ = 31997182818. Its totient is φ = 31997182816.

The previous prime is 31997182787. The next prime is 31997182871. The reversal of 31997182817 is 71828179913.

It is a happy number.

Together with next prime (31997182871) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31906533376 + 90649441 = 178624^2 + 9521^2 .

It is a cyclic number.

It is not a de Polignac number, because 31997182817 - 2⁶ = 31997182753 is a prime.

It is not a weakly prime, because it can be changed into another prime (31997182117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15998591408 + 15998591409.

It is an arithmetic number, because the mean of its divisors is an integer number (15998591409).

Almost surely, 2^31997182817 is an apocalyptic number.

It is an amenable number.

31997182817 is a deficient number, since it is larger than the sum of its proper divisors (1).

31997182817 is an equidigital number, since it uses as much as digits as its factorization.

31997182817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1524096, while the sum is 56.

The spelling of 31997182817 in words is "thirty-one billion, nine hundred ninety-seven million, one hundred eighty-two thousand, eight hundred seventeen".