1231220331 has 40 divisors (see below), whose sum is σ = 2010294000. Its totient is φ = 744759360.

The previous prime is 1231220303. The next prime is 1231220351. The reversal of 1231220331 is 1330221321.

1231220331 is a `hidden beast` number, since 1 + 2 + 312 + 20 + 331 = 666.

It is not a de Polignac number, because 1231220331 - 2⁶ = 1231220267 is a prime.

It is a super-2 number, since 2×1231220331² = 3031807006935499122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1231220351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 630745 + ... + 632693.

It is an arithmetic number, because the mean of its divisors is an integer number (50257350).

Almost surely, 2^1231220331 is an apocalyptic number.

1231220331 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1231220331 is a deficient number, since it is larger than the sum of its proper divisors (779073669).

1231220331 is a wasteful number, since it uses less digits than its factorization.

1231220331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2681 (or 2672 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 1231220331 is about 35088.7493507534. The cubic root of 1231220331 is about 1071.7954921360.

Adding to 1231220331 its reverse (1330221321), we get a palindrome (2561441652).

The spelling of 1231220331 in words is "one billion, two hundred thirty-one million, two hundred twenty thousand, three hundred thirty-one".