129823831 has 2 divisors, whose sum is σ = 129823832. Its totient is φ = 129823830.

The previous prime is 129823739. The next prime is 129823843. The reversal of 129823831 is 138328921.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129823831 is a prime.

It is a super-2 number, since 2×129823831² = 33708454191033122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129823231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64911915 + 64911916.

It is an arithmetic number, because the mean of its divisors is an integer number (64911916).

Almost surely, 2^129823831 is an apocalyptic number.

129823831 is a deficient number, since it is larger than the sum of its proper divisors (1).

129823831 is an equidigital number, since it uses as much as digits as its factorization.

129823831 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 37.

The square root of 129823831 is about 11394.0261102035. The cubic root of 129823831 is about 506.3507686214.

The spelling of 129823831 in words is "one hundred twenty-nine million, eight hundred twenty-three thousand, eight hundred thirty-one".