231210137 has 2 divisors, whose sum is σ = 231210138. Its totient is φ = 231210136.

The previous prime is 231210131. The next prime is 231210139. The reversal of 231210137 is 731012132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 227285776 + 3924361 = 15076^2 + 1981^2 .

It is a cyclic number.

It is not a de Polignac number, because 231210137 - 2¹⁰ = 231209113 is a prime.

Together with 231210139, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (231210131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115605068 + 115605069.

It is an arithmetic number, because the mean of its divisors is an integer number (115605069).

Almost surely, 2^231210137 is an apocalyptic number.

It is an amenable number.

231210137 is a deficient number, since it is larger than the sum of its proper divisors (1).

231210137 is an equidigital number, since it uses as much as digits as its factorization.

231210137 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 252, while the sum is 20.

The square root of 231210137 is about 15205.5955818902. The cubic root of 231210137 is about 613.7652419812.

Adding to 231210137 its reverse (731012132), we get a palindrome (962222269).

The spelling of 231210137 in words is "two hundred thirty-one million, two hundred ten thousand, one hundred thirty-seven".