129913218 has 48 divisors (see below), whose sum is σ = 299009880. Its totient is φ = 40624128.

The previous prime is 129913213. The next prime is 129913247. The reversal of 129913218 is 812319921.

It can be written as a sum of positive squares in 4 ways, for example, as 113486409 + 16426809 = 10653^2 + 4053^2 .

It is a super-2 number, since 2×129913218² = 33754888422231048, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (129913213) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 139378 + ... + 140306.

Almost surely, 2^129913218 is an apocalyptic number.

129913218 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 129913218, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149504940).

129913218 is an abundant number, since it is smaller than the sum of its proper divisors (169096662).

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

129913218 is a wasteful number, since it uses less digits than its factorization.

129913218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1411 (or 1408 counting only the distinct ones).

The product of its digits is 7776, while the sum is 36.

The square root of 129913218 is about 11397.9479732099. The cubic root of 129913218 is about 506.4669537417.

The spelling of 129913218 in words is "one hundred twenty-nine million, nine hundred thirteen thousand, two hundred eighteen".