1231020331 has 4 divisors (see below), whose sum is σ = 1233207432. Its totient is φ = 1228833232.

The previous prime is 1231020311. The next prime is 1231020353. The reversal of 1231020331 is 1330201321.

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 1231020331 - 2⁹ = 1231019819 is a prime.

It is a super-2 number, since 2×1231020331² = 3030822110670699122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231020311) 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 3 ways as a sum of consecutive naturals, for example, 1092706 + ... + 1093831.

It is an arithmetic number, because the mean of its divisors is an integer number (308301858).

Almost surely, 2^1231020331 is an apocalyptic number.

1231020331 is a deficient number, since it is larger than the sum of its proper divisors (2187101).

1231020331 is an equidigital number, since it uses as much as digits as its factorization.

1231020331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2187100.

The product of its (nonzero) digits is 108, while the sum is 16.

The square root of 1231020331 is about 35085.8993186722. The cubic root of 1231020331 is about 1071.7374546748.

Adding to 1231020331 its reverse (1330201321), we get a palindrome (2561221652).

The spelling of 1231020331 in words is "one billion, two hundred thirty-one million, twenty thousand, three hundred thirty-one".