231220718917 has 2 divisors, whose sum is σ = 231220718918. Its totient is φ = 231220718916.

The previous prime is 231220718887. The next prime is 231220718933. The reversal of 231220718917 is 719817022132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 120891117636 + 110329601281 = 347694^2 + 332159^2 .

It is a cyclic number.

It is not a de Polignac number, because 231220718917 - 2⁷ = 231220718789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231220718987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115610359458 + 115610359459.

It is an arithmetic number, because the mean of its divisors is an integer number (115610359459).

Almost surely, 2^231220718917 is an apocalyptic number.

It is an amenable number.

231220718917 is a deficient number, since it is larger than the sum of its proper divisors (1).

231220718917 is an equidigital number, since it uses as much as digits as its factorization.

231220718917 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 84672, while the sum is 43.

The spelling of 231220718917 in words is "two hundred thirty-one billion, two hundred twenty million, seven hundred eighteen thousand, nine hundred seventeen".