129402820 has 12 divisors (see below), whose sum is σ = 271745964. Its totient is φ = 51761120.

The previous prime is 129402817. The next prime is 129402821. The reversal of 129402820 is 28204921.

It can be written as a sum of positive squares in 2 ways, for example, as 51151104 + 78251716 = 7152^2 + 8846^2 .

It is not an unprimeable number, because it can be changed into a prime (129402821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3235051 + ... + 3235090.

It is an arithmetic number, because the mean of its divisors is an integer number (22645497).

Almost surely, 2^129402820 is an apocalyptic number.

129402820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129402820 is an abundant number, since it is smaller than the sum of its proper divisors (142343144).

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

129402820 is a wasteful number, since it uses less digits than its factorization.

129402820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6470150 (or 6470148 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 129402820 is about 11375.5360313262. The cubic root of 129402820 is about 505.8028206819.

The spelling of 129402820 in words is "one hundred twenty-nine million, four hundred two thousand, eight hundred twenty".