231513 has 4 divisors (see below), whose sum is σ = 308688. Its totient is φ = 154340.

The previous prime is 231503. The next prime is 231529. The reversal of 231513 is 315132.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 231513 - 2⁵ = 231481 is a prime.

It is a D-number.

It is a junction number, because it is equal to n+sod(n) for n = 231492 and 231501.

It is not an unprimeable number, because it can be changed into a prime (231503) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38583 + ... + 38588.

It is an arithmetic number, because the mean of its divisors is an integer number (77172).

2²³¹⁵¹³ is an apocalyptic number.

It is an amenable number.

231513 is a deficient number, since it is larger than the sum of its proper divisors (77175).

231513 is an equidigital number, since it uses as much as digits as its factorization.

231513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77174.

The product of its digits is 90, while the sum is 15.

The square root of 231513 is about 481.1579782151. The cubic root of 231513 is about 61.4033116160.

Adding to 231513 its reverse (315132), we get a palindrome (546645).

The spelling of 231513 in words is "two hundred thirty-one thousand, five hundred thirteen".