129417840 has 120 divisors (see below), whose sum is σ = 437561280. Its totient is φ = 34278912.

The previous prime is 129417817. The next prime is 129417929. The reversal of 129417840 is 48714921.

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

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 129417795 and 129417804.

It is a congruent number.

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, 124041 + ... + 125079.

It is an arithmetic number, because the mean of its divisors is an integer number (3646344).

Almost surely, 2^129417840 is an apocalyptic number.

129417840 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 129417840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (218780640).

129417840 is an abundant number, since it is smaller than the sum of its proper divisors (308143440).

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

129417840 is a wasteful number, since it uses less digits than its factorization.

129417840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1231 (or 1222 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 129417840 is about 11376.1962008397. The cubic root of 129417840 is about 505.8223897156.

The spelling of 129417840 in words is "one hundred twenty-nine million, four hundred seventeen thousand, eight hundred forty".