231133531 has 4 divisors (see below), whose sum is σ = 231389272. Its totient is φ = 230877792.

The previous prime is 231133517. The next prime is 231133541. The reversal of 231133531 is 135331132.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 231133531 - 2¹⁵ = 231100763 is a prime.

It is a super-3 number, since 3×231133531³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231133501) 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, 126510 + ... + 128323.

It is an arithmetic number, because the mean of its divisors is an integer number (57847318).

Almost surely, 2^231133531 is an apocalyptic number.

231133531 is a deficient number, since it is larger than the sum of its proper divisors (255741).

231133531 is an equidigital number, since it uses as much as digits as its factorization.

231133531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255740.

The product of its digits is 810, while the sum is 22.

The square root of 231133531 is about 15203.0763663148. The cubic root of 231133531 is about 613.6974489706.

Adding to 231133531 its reverse (135331132), we get a palindrome (366464663).

The spelling of 231133531 in words is "two hundred thirty-one million, one hundred thirty-three thousand, five hundred thirty-one".