1231961231 has 2 divisors, whose sum is σ = 1231961232. Its totient is φ = 1231961230.

The previous prime is 1231961201. The next prime is 1231961239. The reversal of 1231961231 is 1321691321.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1231961231 - 2¹⁸ = 1231699087 is a prime.

It is a super-2 number, since 2×1231961231² = 3035456949374070722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1231961194 and 1231961203.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1231961239) 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 as a sum of consecutive naturals, namely, 615980615 + 615980616.

It is an arithmetic number, because the mean of its divisors is an integer number (615980616).

Almost surely, 2^1231961231 is an apocalyptic number.

1231961231 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231961231 is an equidigital number, since it uses as much as digits as its factorization.

1231961231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1944, while the sum is 29.

The square root of 1231961231 is about 35099.3052780251. The cubic root of 1231961231 is about 1072.0104371594.

The spelling of 1231961231 in words is "one billion, two hundred thirty-one million, nine hundred sixty-one thousand, two hundred thirty-one".