129020940 has 36 divisors (see below), whose sum is σ = 391364064. Its totient is φ = 34405536.

The previous prime is 129020933. The next prime is 129020953. The reversal of 129020940 is 49020921.

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 358212 + ... + 358571.

It is an arithmetic number, because the mean of its divisors is an integer number (10871224).

Almost surely, 2^129020940 is an apocalyptic number.

129020940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129020940 is an abundant number, since it is smaller than the sum of its proper divisors (262343124).

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

129020940 is a wasteful number, since it uses less digits than its factorization.

129020940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 716798 (or 716793 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 129020940 is about 11358.7384862933. The cubic root of 129020940 is about 505.3047730595.

The spelling of 129020940 in words is "one hundred twenty-nine million, twenty thousand, nine hundred forty".