129858640 has 20 divisors (see below), whose sum is σ = 301921524. Its totient is φ = 51943424.

The previous prime is 129858623. The next prime is 129858647. The reversal of 129858640 is 46858921.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 99520576 + 30338064 = 9976^2 + 5508^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129858647) 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, 811537 + ... + 811696.

Almost surely, 2^129858640 is an apocalyptic number.

129858640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129858640 is an abundant number, since it is smaller than the sum of its proper divisors (172062884).

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

129858640 is a wasteful number, since it uses less digits than its factorization.

129858640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1623246 (or 1623240 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 43.

The square root of 129858640 is about 11395.5535188072. The cubic root of 129858640 is about 506.3960196581.

The spelling of 129858640 in words is "one hundred twenty-nine million, eight hundred fifty-eight thousand, six hundred forty".