231000813 has 12 divisors (see below), whose sum is σ = 333862620. Its totient is φ = 153910656.

The previous prime is 231000787. The next prime is 231000853. The reversal of 231000813 is 318000132.

It can be written as a sum of positive squares in 2 ways, for example, as 47858724 + 183142089 = 6918^2 + 13533^2 .

It is not a de Polignac number, because 231000813 - 2¹⁰ = 230999789 is a prime.

It is a super-2 number, since 2×231000813² = 106722751213321938, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231000853) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11253 + ... + 24261.

It is an arithmetic number, because the mean of its divisors is an integer number (27821885).

Almost surely, 2^231000813 is an apocalyptic number.

It is an amenable number.

231000813 is a deficient number, since it is larger than the sum of its proper divisors (102861807).

231000813 is a wasteful number, since it uses less digits than its factorization.

231000813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14988 (or 14985 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 231000813 is about 15198.7108992835. The cubic root of 231000813 is about 613.5799637921.

Adding to 231000813 its reverse (318000132), we get a palindrome (549000945).

The spelling of 231000813 in words is "two hundred thirty-one million, eight hundred thirteen", and thus it is an aban number.