129256120 has 64 divisors (see below), whose sum is σ = 339192000. Its totient is φ = 44311680.

The previous prime is 129256111. The next prime is 129256181. The reversal of 129256120 is 21652921.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9010 + ... + 18430.

It is an arithmetic number, because the mean of its divisors is an integer number (5299875).

Almost surely, 2^129256120 is an apocalyptic number.

129256120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129256120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169596000).

129256120 is an abundant number, since it is smaller than the sum of its proper divisors (209935880).

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

129256120 is an equidigital number, since it uses as much as digits as its factorization.

129256120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9453 (or 9435 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 129256120 is about 11369.0861550082. The cubic root of 129256120 is about 505.6116107032.

The spelling of 129256120 in words is "one hundred twenty-nine million, two hundred fifty-six thousand, one hundred twenty".