1331123231 has 4 divisors (see below), whose sum is σ = 1332157200. Its totient is φ = 1330089264.

The previous prime is 1331123221. The next prime is 1331123263. The reversal of 1331123231 is 1323211331.

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 1331123231 - 2³⁰ = 257381407 is a prime.

It is a super-2 number, since 2×1331123231² = 3543778112215758722, 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 (1331123221) 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, 515051 + ... + 517628.

It is an arithmetic number, because the mean of its divisors is an integer number (333039300).

Almost surely, 2^1331123231 is an apocalyptic number.

1331123231 is a deficient number, since it is larger than the sum of its proper divisors (1033969).

1331123231 is a wasteful number, since it uses less digits than its factorization.

1331123231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1033968.

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

The square root of 1331123231 is about 36484.5615432062. The cubic root of 1331123231 is about 1100.0339468862.

Adding to 1331123231 its reverse (1323211331), we get a palindrome (2654334562).

It can be divided in two parts, 1331 and 123231, that multiplied together give a palindrome (164020461).

The spelling of 1331123231 in words is "one billion, three hundred thirty-one million, one hundred twenty-three thousand, two hundred thirty-one".