231317381861 has 2 divisors, whose sum is σ = 231317381862. Its totient is φ = 231317381860.

The previous prime is 231317381843. The next prime is 231317381909. The reversal of 231317381861 is 168183713132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 228971820100 + 2345561761 = 478510^2 + 48431^2 .

It is a cyclic number.

It is not a de Polignac number, because 231317381861 - 2²² = 231313187557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231317381261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115658690930 + 115658690931.

It is an arithmetic number, because the mean of its divisors is an integer number (115658690931).

Almost surely, 2^231317381861 is an apocalyptic number.

It is an amenable number.

231317381861 is a deficient number, since it is larger than the sum of its proper divisors (1).

231317381861 is an equidigital number, since it uses as much as digits as its factorization.

231317381861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 44.

The spelling of 231317381861 in words is "two hundred thirty-one billion, three hundred seventeen million, three hundred eighty-one thousand, eight hundred sixty-one".