129240720 has 120 divisors (see below), whose sum is σ = 496057536. Its totient is φ = 29539584.

The previous prime is 129240691. The next prime is 129240737. The reversal of 129240720 is 27042921.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×129240720² = 33406327412236800, which contains 22 as substring.

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, 7782 + ... + 17861.

Almost surely, 2^129240720 is an apocalyptic number.

129240720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129240720 is an abundant number, since it is smaller than the sum of its proper divisors (366816816).

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

129240720 is a wasteful number, since it uses less digits than its factorization.

129240720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25669 (or 25660 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 129240720 is about 11368.4088596426. The cubic root of 129240720 is about 505.5915298279.

The spelling of 129240720 in words is "one hundred twenty-nine million, two hundred forty thousand, seven hundred twenty".