129421640 has 64 divisors (see below), whose sum is σ = 298080000. Its totient is φ = 50561280.

The previous prime is 129421639. The next prime is 129421723. The reversal of 129421640 is 46124921.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 565046 + ... + 565274.

It is an arithmetic number, because the mean of its divisors is an integer number (4657500).

Almost surely, 2^129421640 is an apocalyptic number.

129421640 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 129421640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149040000).

129421640 is an abundant number, since it is smaller than the sum of its proper divisors (168658360).

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

129421640 is a wasteful number, since it uses less digits than its factorization.

129421640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510 (or 506 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 129421640 is about 11376.3632150174. The cubic root of 129421640 is about 505.8273403630.

The spelling of 129421640 in words is "one hundred twenty-nine million, four hundred twenty-one thousand, six hundred forty".