129891818 has 16 divisors (see below), whose sum is σ = 222820224. Its totient is φ = 55630800.

The previous prime is 129891803. The next prime is 129891857. The reversal of 129891818 is 818198921.

It is a super-3 number, since 3×129891818³ (a number of 25 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33896 + ... + 37532.

It is an arithmetic number, because the mean of its divisors is an integer number (13926264).

Almost surely, 2^129891818 is an apocalyptic number.

129891818 is a deficient number, since it is larger than the sum of its proper divisors (92928406).

129891818 is a wasteful number, since it uses less digits than its factorization.

129891818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6197.

The product of its digits is 82944, while the sum is 47.

The square root of 129891818 is about 11397.0091690759. The cubic root of 129891818 is about 506.4391428996.

The spelling of 129891818 in words is "one hundred twenty-nine million, eight hundred ninety-one thousand, eight hundred eighteen".