129231620 has 72 divisors (see below), whose sum is σ = 334307736. Its totient is φ = 41696256.

The previous prime is 129231607. The next prime is 129231701. The reversal of 129231620 is 26132921.

It can be written as a sum of positive squares in 4 ways, for example, as 46676224 + 82555396 = 6832^2 + 9086^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 129231620.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12782 + ... + 20538.

It is an arithmetic number, because the mean of its divisors is an integer number (4643163).

Almost surely, 2^129231620 is an apocalyptic number.

129231620 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 129231620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (167153868).

129231620 is an abundant number, since it is smaller than the sum of its proper divisors (205076116).

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

129231620 is a wasteful number, since it uses less digits than its factorization.

129231620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7797 (or 7788 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 129231620 is about 11368.0086206864. The cubic root of 129231620 is about 505.5796631064.

The spelling of 129231620 in words is "one hundred twenty-nine million, two hundred thirty-one thousand, six hundred twenty".