129400440 has 128 divisors (see below), whose sum is σ = 422452800. Its totient is φ = 31518720.

The previous prime is 129400429. The next prime is 129400441. The reversal of 129400440 is 44004921.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 129400440.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129400441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 169660 + ... + 170420.

Almost surely, 2^129400440 is an apocalyptic number.

129400440 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 129400440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (211226400).

129400440 is an abundant number, since it is smaller than the sum of its proper divisors (293052360).

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

129400440 is a wasteful number, since it uses less digits than its factorization.

129400440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 897 (or 893 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 129400440 is about 11375.4314203902. The cubic root of 129400440 is about 505.7997197240.

The spelling of 129400440 in words is "one hundred twenty-nine million, four hundred thousand, four hundred forty".