231312515009 has 4 divisors (see below), whose sum is σ = 239288808660. Its totient is φ = 223336221360.

The previous prime is 231312515003. The next prime is 231312515011. The reversal of 231312515009 is 900515213132.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 88804000000 + 142508515009 = 298000^2 + 377503^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231312515009 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (231312515003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3988146782 + ... + 3988146839.

It is an arithmetic number, because the mean of its divisors is an integer number (59822202165).

Almost surely, 2^231312515009 is an apocalyptic number.

231312515009 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

231312515009 is a deficient number, since it is larger than the sum of its proper divisors (7976293651).

231312515009 is an equidigital number, since it uses as much as digits as its factorization.

231312515009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7976293650.

The product of its (nonzero) digits is 8100, while the sum is 32.

The spelling of 231312515009 in words is "two hundred thirty-one billion, three hundred twelve million, five hundred fifteen thousand, nine".