129825931 has 4 divisors (see below), whose sum is σ = 130110472. Its totient is φ = 129541392.

The previous prime is 129825919. The next prime is 129825937. The reversal of 129825931 is 139528921.

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 129825931 - 2⁹ = 129825419 is a prime.

It is a super-2 number, since 2×129825931² = 33709544720033522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129825937) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 141585 + ... + 142498.

It is an arithmetic number, because the mean of its divisors is an integer number (32527618).

Almost surely, 2^129825931 is an apocalyptic number.

129825931 is a deficient number, since it is larger than the sum of its proper divisors (284541).

129825931 is an equidigital number, since it uses as much as digits as its factorization.

129825931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284540.

The product of its digits is 38880, while the sum is 40.

The square root of 129825931 is about 11394.1182633848. The cubic root of 129825931 is about 506.3534988106.

The spelling of 129825931 in words is "one hundred twenty-nine million, eight hundred twenty-five thousand, nine hundred thirty-one".