231513137 has 2 divisors, whose sum is σ = 231513138. Its totient is φ = 231513136.

The previous prime is 231513133. The next prime is 231513143. The reversal of 231513137 is 731315132.

231513137 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 185395456 + 46117681 = 13616^2 + 6791^2 .

It is a cyclic number.

It is not a de Polignac number, because 231513137 - 2² = 231513133 is a prime.

It is not a weakly prime, because it can be changed into another prime (231513133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115756568 + 115756569.

It is an arithmetic number, because the mean of its divisors is an integer number (115756569).

Almost surely, 2^231513137 is an apocalyptic number.

It is an amenable number.

231513137 is a deficient number, since it is larger than the sum of its proper divisors (1).

231513137 is an equidigital number, since it uses as much as digits as its factorization.

231513137 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1890, while the sum is 26.

The square root of 231513137 is about 15215.5557571848. Note that the first 3 decimals coincide. The cubic root of 231513137 is about 614.0332372802.

Adding to 231513137 its reverse (731315132), we get a palindrome (962828269).

The spelling of 231513137 in words is "two hundred thirty-one million, five hundred thirteen thousand, one hundred thirty-seven".