129820100 has 36 divisors (see below), whose sum is σ = 282989700. Its totient is φ = 51692160.

The previous prime is 129820091. The next prime is 129820121. The reversal of 129820100 is 1028921.

It can be written as a sum of positive squares in 6 ways, for example, as 42436 + 129777664 = 206^2 + 11392^2 .

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, 20066 + ... + 25734.

It is an arithmetic number, because the mean of its divisors is an integer number (7860825).

Almost surely, 2^129820100 is an apocalyptic number.

129820100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129820100 is an abundant number, since it is smaller than the sum of its proper divisors (153169600).

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

129820100 is a wasteful number, since it uses less digits than its factorization.

129820100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5912 (or 5905 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 129820100 is about 11393.8623828797. The cubic root of 129820100 is about 506.3459179125.

The spelling of 129820100 in words is "one hundred twenty-nine million, eight hundred twenty thousand, one hundred".