129072820 has 24 divisors (see below), whose sum is σ = 275101344. Its totient is φ = 50858016.

The previous prime is 129072791. The next prime is 129072821. The reversal of 129072820 is 28270921.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129072821) 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 in 7 ways as a sum of consecutive naturals, for example, 46822 + ... + 49501.

It is an arithmetic number, because the mean of its divisors is an integer number (11462556).

Almost surely, 2^129072820 is an apocalyptic number.

129072820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129072820 is an abundant number, since it is smaller than the sum of its proper divisors (146028524).

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

129072820 is a wasteful number, since it uses less digits than its factorization.

129072820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96399 (or 96397 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 129072820 is about 11361.0219610737. The cubic root of 129072820 is about 505.3724925543.

The spelling of 129072820 in words is "one hundred twenty-nine million, seventy-two thousand, eight hundred twenty".