129804820 has 24 divisors (see below), whose sum is σ = 272953800. Its totient is φ = 51852672.

The previous prime is 129804799. The next prime is 129804907. The reversal of 129804820 is 28408921.

It can be written as a sum of positive squares in 4 ways, for example, as 2972176 + 126832644 = 1724^2 + 11262^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12666 + ... + 20494.

It is an arithmetic number, because the mean of its divisors is an integer number (11373075).

Almost surely, 2^129804820 is an apocalyptic number.

129804820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129804820 is an abundant number, since it is smaller than the sum of its proper divisors (143148980).

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

129804820 is a wasteful number, since it uses less digits than its factorization.

129804820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8667 (or 8665 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 34.

The square root of 129804820 is about 11393.1918267007. The cubic root of 129804820 is about 506.3260512683.

The spelling of 129804820 in words is "one hundred twenty-nine million, eight hundred four thousand, eight hundred twenty".