129384820 has 12 divisors (see below), whose sum is σ = 271708164. Its totient is φ = 51753920.

The previous prime is 129384809. The next prime is 129384833. The reversal of 129384820 is 28483921.

It can be written as a sum of positive squares in 2 ways, for example, as 21141604 + 108243216 = 4598^2 + 10404^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 129384820.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3234601 + ... + 3234640.

It is an arithmetic number, because the mean of its divisors is an integer number (22642347).

Almost surely, 2^129384820 is an apocalyptic number.

129384820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129384820 is an abundant number, since it is smaller than the sum of its proper divisors (142323344).

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

129384820 is a wasteful number, since it uses less digits than its factorization.

129384820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6469250 (or 6469248 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 37.

The square root of 129384820 is about 11374.7448323028. The cubic root of 129384820 is about 505.7793671153.

The spelling of 129384820 in words is "one hundred twenty-nine million, three hundred eighty-four thousand, eight hundred twenty".