129899840 has 56 divisors (see below), whose sum is σ = 353519232. Its totient is φ = 44536320.

The previous prime is 129899813. The next prime is 129899863. The reversal of 129899840 is 48998921.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (56).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26756 + ... + 31235.

Almost surely, 2^129899840 is an apocalyptic number.

129899840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129899840 is an abundant number, since it is smaller than the sum of its proper divisors (223619392).

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

129899840 is an equidigital number, since it uses as much as digits as its factorization.

129899840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58015 (or 58005 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 50.

The square root of 129899840 is about 11397.3610980788. The cubic root of 129899840 is about 506.4495684246.

The spelling of 129899840 in words is "one hundred twenty-nine million, eight hundred ninety-nine thousand, eight hundred forty".