1231133231 has 4 divisors (see below), whose sum is σ = 1233804264. Its totient is φ = 1228462200.

The previous prime is 1231133209. The next prime is 1231133269. The reversal of 1231133231 is 1323311321.

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 1231133231 - 2¹⁰ = 1231132207 is a prime.

It is a super-2 number, since 2×1231133231² = 3031378064944998722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231163231) 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, 1334825 + ... + 1335746.

It is an arithmetic number, because the mean of its divisors is an integer number (308451066).

Almost surely, 2^1231133231 is an apocalyptic number.

1231133231 is a deficient number, since it is larger than the sum of its proper divisors (2671033).

1231133231 is an equidigital number, since it uses as much as digits as its factorization.

1231133231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2671032.

The product of its digits is 324, while the sum is 20.

The square root of 1231133231 is about 35087.5081902377. The cubic root of 1231133231 is about 1071.7702175942.

Adding to 1231133231 its reverse (1323311321), we get a palindrome (2554444552).

The spelling of 1231133231 in words is "one billion, two hundred thirty-one million, one hundred thirty-three thousand, two hundred thirty-one".