129000920 has 32 divisors (see below), whose sum is σ = 299617920. Its totient is φ = 49935360.

The previous prime is 129000901. The next prime is 129000923. The reversal of 129000920 is 29000921.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129000923) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50777 + ... + 53256.

It is an arithmetic number, because the mean of its divisors is an integer number (9363060).

Almost surely, 2^129000920 is an apocalyptic number.

129000920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129000920 is an abundant number, since it is smaller than the sum of its proper divisors (170617000).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

129000920 is a wasteful number, since it uses less digits than its factorization.

129000920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104075 (or 104071 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 129000920 is about 11357.8571922700. The cubic root of 129000920 is about 505.2786358943.

Subtracting from 129000920 its reverse (29000921), we obtain a palindrome (99999999).

The spelling of 129000920 in words is "one hundred twenty-nine million, nine hundred twenty", and thus it is an aban number.