129319820 has 36 divisors (see below), whose sum is σ = 315912240. Its totient is φ = 44337888.

The previous prime is 129319807. The next prime is 129319859. The reversal of 129319820 is 28913921.

It is a Harshad number since it is a multiple of its sum of digits (35).

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, 65000 + ... + 66959.

It is an arithmetic number, because the mean of its divisors is an integer number (8775340).

Almost surely, 2^129319820 is an apocalyptic number.

129319820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129319820 is an abundant number, since it is smaller than the sum of its proper divisors (186592420).

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

129319820 is a wasteful number, since it uses less digits than its factorization.

129319820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131982 (or 131973 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 129319820 is about 11371.8872664127. The cubic root of 129319820 is about 505.6946555659.

The spelling of 129319820 in words is "one hundred twenty-nine million, three hundred nineteen thousand, eight hundred twenty".