129671640 has 144 divisors (see below), whose sum is σ = 490304880. Its totient is φ = 29635200.

The previous prime is 129671639. The next prime is 129671651. The reversal of 129671640 is 46176921.

129671640 is a `hidden beast` number, since 1 + 2 + 9 + 6 + 7 + 1 + 640 = 666.

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 = 129671595 and 129671604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 13965 + ... + 21315.

It is an arithmetic number, because the mean of its divisors is an integer number (3404895).

Almost surely, 2^129671640 is an apocalyptic number.

129671640 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 129671640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (245152440).

129671640 is an abundant number, since it is smaller than the sum of its proper divisors (360633240).

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

129671640 is a wasteful number, since it uses less digits than its factorization.

129671640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7382 (or 7368 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 129671640 is about 11387.3456081740. The cubic root of 129671640 is about 506.1528281717.

The spelling of 129671640 in words is "one hundred twenty-nine million, six hundred seventy-one thousand, six hundred forty".