129212220 has 48 divisors (see below), whose sum is σ = 362442528. Its totient is φ = 34394880.

The previous prime is 129212191. The next prime is 129212231. The reversal of 129212220 is 22212921.

It is a happy number.

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, 39030 + ... + 42210.

It is an arithmetic number, because the mean of its divisors is an integer number (7550886).

Almost surely, 2^129212220 is an apocalyptic number.

129212220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129212220 is an abundant number, since it is smaller than the sum of its proper divisors (233230308).

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

129212220 is a wasteful number, since it uses less digits than its factorization.

129212220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3870 (or 3868 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 129212220 is about 11367.1553169648. The cubic root of 129212220 is about 505.5543629610.

The spelling of 129212220 in words is "one hundred twenty-nine million, two hundred twelve thousand, two hundred twenty".