1231321331 has 4 divisors (see below), whose sum is σ = 1231482000. Its totient is φ = 1231160664.

The previous prime is 1231321313. The next prime is 1231321361. The reversal of 1231321331 is 1331231321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1331231321 = 7 ⋅190175903.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1231321331 is a prime.

It is a super-2 number, since 2×1231321331² = 3032304440351223122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231321361) 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, 68231 + ... + 84368.

It is an arithmetic number, because the mean of its divisors is an integer number (307870500).

Almost surely, 2^1231321331 is an apocalyptic number.

1231321331 is a deficient number, since it is larger than the sum of its proper divisors (160669).

1231321331 is an equidigital number, since it uses as much as digits as its factorization.

1231321331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160668.

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

The square root of 1231321331 is about 35090.1885289891. The cubic root of 1231321331 is about 1071.8247986654.

Adding to 1231321331 its reverse (1331231321), we get a palindrome (2562552652).

The spelling of 1231321331 in words is "one billion, two hundred thirty-one million, three hundred twenty-one thousand, three hundred thirty-one".