129180640 has 24 divisors (see below), whose sum is σ = 305189640. Its totient is φ = 51672192.

The previous prime is 129180617. The next prime is 129180641. The reversal of 129180640 is 46081921.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129180641) 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, 403530 + ... + 403849.

It is an arithmetic number, because the mean of its divisors is an integer number (12716235).

Almost surely, 2^129180640 is an apocalyptic number.

129180640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129180640 is an abundant number, since it is smaller than the sum of its proper divisors (176009000).

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

129180640 is an equidigital number, since it uses as much as digits as its factorization.

129180640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 807394 (or 807386 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 129180640 is about 11365.7661422361. The cubic root of 129180640 is about 505.5131730807.

The spelling of 129180640 in words is "one hundred twenty-nine million, one hundred eighty thousand, six hundred forty".