129923831 has 2 divisors, whose sum is σ = 129923832. Its totient is φ = 129923830.

The previous prime is 129923797. The next prime is 129923861. The reversal of 129923831 is 138329921.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129923831 is a prime.

It is a super-2 number, since 2×129923831² = 33760403723433122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129923861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64961915 + 64961916.

It is an arithmetic number, because the mean of its divisors is an integer number (64961916).

Almost surely, 2^129923831 is an apocalyptic number.

129923831 is a deficient number, since it is larger than the sum of its proper divisors (1).

129923831 is an equidigital number, since it uses as much as digits as its factorization.

129923831 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23328, while the sum is 38.

The square root of 129923831 is about 11398.4135299611. The cubic root of 129923831 is about 506.4807449671.

The spelling of 129923831 in words is "one hundred twenty-nine million, nine hundred twenty-three thousand, eight hundred thirty-one".