129758440 has 128 divisors (see below), whose sum is σ = 348364800. Its totient is φ = 42577920.

The previous prime is 129758423. The next prime is 129758443. The reversal of 129758440 is 44857921.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 129758393 and 129758402.

It is not an unprimeable number, because it can be changed into a prime (129758443) 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, 1021657 + ... + 1021783.

It is an arithmetic number, because the mean of its divisors is an integer number (2721600).

Almost surely, 2^129758440 is an apocalyptic number.

129758440 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 129758440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (174182400).

129758440 is an abundant number, since it is smaller than the sum of its proper divisors (218606360).

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

129758440 is a wasteful number, since it uses less digits than its factorization.

129758440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 275 (or 271 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 40.

The square root of 129758440 is about 11391.1562187515. The cubic root of 129758440 is about 506.2657396925.

The spelling of 129758440 in words is "one hundred twenty-nine million, seven hundred fifty-eight thousand, four hundred forty".