129656560 has 80 divisors (see below), whose sum is σ = 330728832. Its totient is φ = 46880000.

The previous prime is 129656521. The next prime is 129656561. The reversal of 129656560 is 65656921.

It is a tau number, because it is divible by the number of its divisors (80).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129656561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 220587 + ... + 221173.

Almost surely, 2^129656560 is an apocalyptic number.

129656560 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 129656560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (165364416).

129656560 is an abundant number, since it is smaller than the sum of its proper divisors (201072272).

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

129656560 is a wasteful number, since it uses less digits than its factorization.

129656560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 862 (or 856 counting only the distinct ones).

The product of its (nonzero) digits is 97200, while the sum is 40.

The square root of 129656560 is about 11386.6834504170. The cubic root of 129656560 is about 506.1332066093.

The spelling of 129656560 in words is "one hundred twenty-nine million, six hundred fifty-six thousand, five hundred sixty".