129756640 has 48 divisors (see below), whose sum is σ = 330136128. Its totient is φ = 47909376.

The previous prime is 129756623. The next prime is 129756661. The reversal of 129756640 is 46657921.

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 = 129756593 and 129756602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29112 + ... + 33271.

It is an arithmetic number, because the mean of its divisors is an integer number (6877836).

Almost surely, 2^129756640 is an apocalyptic number.

129756640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129756640 is an abundant number, since it is smaller than the sum of its proper divisors (200379488).

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

129756640 is a wasteful number, since it uses less digits than its factorization.

129756640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62411 (or 62403 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 40.

The square root of 129756640 is about 11391.0772098165. The cubic root of 129756640 is about 506.2633987207.

The spelling of 129756640 in words is "one hundred twenty-nine million, seven hundred fifty-six thousand, six hundred forty".