231871610813 has 2 divisors, whose sum is σ = 231871610814. Its totient is φ = 231871610812.

The previous prime is 231871610783. The next prime is 231871610819. The reversal of 231871610813 is 318016178132.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 223764949444 + 8106661369 = 473038^2 + 90037^2 .

It is a cyclic number.

It is not a de Polignac number, because 231871610813 - 2²² = 231867416509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231871610819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115935805406 + 115935805407.

It is an arithmetic number, because the mean of its divisors is an integer number (115935805407).

Almost surely, 2^231871610813 is an apocalyptic number.

It is an amenable number.

231871610813 is a deficient number, since it is larger than the sum of its proper divisors (1).

231871610813 is an equidigital number, since it uses as much as digits as its factorization.

231871610813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48384, while the sum is 41.

Adding to 231871610813 its reverse (318016178132), we get a palindrome (549887788945).

The spelling of 231871610813 in words is "two hundred thirty-one billion, eight hundred seventy-one million, six hundred ten thousand, eight hundred thirteen".