1231231321 has 2 divisors, whose sum is σ = 1231231322. Its totient is φ = 1231231320.

The previous prime is 1231231303. The next prime is 1231231327. The reversal of 1231231321 is 1231321321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1220733721 + 10497600 = 34939^2 + 3240^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1231231321 is a prime.

It is a super-2 number, since 2×1231231321² = 3031861131622810082, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1231231327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615615660 + 615615661.

It is an arithmetic number, because the mean of its divisors is an integer number (615615661).

Almost surely, 2^1231231321 is an apocalyptic number.

It is an amenable number.

1231231321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231231321 is an equidigital number, since it uses as much as digits as its factorization.

1231231321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216, while the sum is 19.

The square root of 1231231321 is about 35088.9059533067. The cubic root of 1231231321 is about 1071.7986811123.

Adding to 1231231321 its reverse (1231321321), we get a palindrome (2462552642).

Subtracting 1231231321 from its reverse (1231321321), we obtain a square (90000 = 300²).

The spelling of 1231231321 in words is "one billion, two hundred thirty-one million, two hundred thirty-one thousand, three hundred twenty-one".