129821760 has 84 divisors (see below), whose sum is σ = 446542668. Its totient is φ = 34618368.

The previous prime is 129821743. The next prime is 129821767. The reversal of 129821760 is 67128921.

It can be written as a sum of positive squares in 2 ways, for example, as 60466176 + 69355584 = 7776^2 + 8328^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (129821767) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19659 + ... + 25418.

Almost surely, 2^129821760 is an apocalyptic number.

129821760 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129821760 is an abundant number, since it is smaller than the sum of its proper divisors (316720908).

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

129821760 is a wasteful number, since it uses less digits than its factorization.

129821760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45100 (or 45087 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 129821760 is about 11393.9352288838. The cubic root of 129821760 is about 506.3480761059.

The spelling of 129821760 in words is "one hundred twenty-nine million, eight hundred twenty-one thousand, seven hundred sixty".