231871513 has 2 divisors, whose sum is σ = 231871514. Its totient is φ = 231871512.

The previous prime is 231871511. The next prime is 231871531. The reversal of 231871513 is 315178132.

Together with next prime (231871531) 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., 208860304 + 23011209 = 14452^2 + 4797^2 .

It is a cyclic number.

It is not a de Polignac number, because 231871513 - 2¹ = 231871511 is a prime.

Together with 231871511, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (231871511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115935756 + 115935757.

It is an arithmetic number, because the mean of its divisors is an integer number (115935757).

Almost surely, 2^231871513 is an apocalyptic number.

It is an amenable number.

231871513 is a deficient number, since it is larger than the sum of its proper divisors (1).

231871513 is an equidigital number, since it uses as much as digits as its factorization.

231871513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 31.

The square root of 231871513 is about 15227.3278351784. The cubic root of 231871513 is about 614.3499094852.

The spelling of 231871513 in words is "two hundred thirty-one million, eight hundred seventy-one thousand, five hundred thirteen".