129321800 has 24 divisors (see below), whose sum is σ = 300673650. Its totient is φ = 51728640.

The previous prime is 129321799. The next prime is 129321821. The reversal of 129321800 is 8123921.

It can be written as a sum of positive squares in 3 ways, for example, as 107288164 + 22033636 = 10358^2 + 4694^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 129321800.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 323105 + ... + 323504.

Almost surely, 2^129321800 is an apocalyptic number.

129321800 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129321800 is an abundant number, since it is smaller than the sum of its proper divisors (171351850).

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

129321800 is a wasteful number, since it uses less digits than its factorization.

129321800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646625 (or 646616 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 129321800 is about 11371.9743228694. The cubic root of 129321800 is about 505.6972364291.

The spelling of 129321800 in words is "one hundred twenty-nine million, three hundred twenty-one thousand, eight hundred".