231513520 has 40 divisors (see below), whose sum is σ = 615165984. Its totient is φ = 79375872.

The previous prime is 231513481. The next prime is 231513521. The reversal of 231513520 is 25315132.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 231513491 and 231513500.

It is not an unprimeable number, because it can be changed into a prime (231513521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 206149 + ... + 207268.

Almost surely, 2^231513520 is an apocalyptic number.

231513520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231513520 is an abundant number, since it is smaller than the sum of its proper divisors (383652464).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

231513520 is a wasteful number, since it uses less digits than its factorization.

231513520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 413437 (or 413431 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 22.

The square root of 231513520 is about 15215.5683429834. The cubic root of 231513520 is about 614.0335758853.

Adding to 231513520 its reverse (25315132), we get a palindrome (256828652).

The spelling of 231513520 in words is "two hundred thirty-one million, five hundred thirteen thousand, five hundred twenty".