129640660 has 12 divisors (see below), whose sum is σ = 272245428. Its totient is φ = 51856256.

The previous prime is 129640649. The next prime is 129640669. The reversal of 129640660 is 66046921.

129640660 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 27751824 + 101888836 = 5268^2 + 10094^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129640669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3240997 + ... + 3241036.

It is an arithmetic number, because the mean of its divisors is an integer number (22687119).

Almost surely, 2^129640660 is an apocalyptic number.

129640660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129640660 is an abundant number, since it is smaller than the sum of its proper divisors (142604768).

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

129640660 is a wasteful number, since it uses less digits than its factorization.

129640660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6482042 (or 6482040 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 129640660 is about 11385.9852450282. The cubic root of 129640660 is about 506.1125164440.

The spelling of 129640660 in words is "one hundred twenty-nine million, six hundred forty thousand, six hundred sixty".