129821772 has 12 divisors (see below), whose sum is σ = 302917496. Its totient is φ = 43273920.

The previous prime is 129821767. The next prime is 129821801. The reversal of 129821772 is 277128921.

129821772 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 129821772.

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, 5409229 + ... + 5409252.

Almost surely, 2^129821772 is an apocalyptic number.

129821772 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

129821772 is an abundant number, since it is smaller than the sum of its proper divisors (173095724).

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

129821772 is a wasteful number, since it uses less digits than its factorization.

129821772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10818488 (or 10818486 counting only the distinct ones).

The product of its digits is 28224, while the sum is 39.

The square root of 129821772 is about 11393.9357554798. The cubic root of 129821772 is about 506.3480917072.

The spelling of 129821772 in words is "one hundred twenty-nine million, eight hundred twenty-one thousand, seven hundred seventy-two".