129189918 has 32 divisors (see below), whose sum is σ = 303553152. Its totient is φ = 36136800.

The previous prime is 129189889. The next prime is 129189923. The reversal of 129189918 is 819981921.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 74428 + ... + 76143.

It is an arithmetic number, because the mean of its divisors is an integer number (9486036).

Almost surely, 2^129189918 is an apocalyptic number.

129189918 is an abundant number, since it is smaller than the sum of its proper divisors (174363234).

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

129189918 is a wasteful number, since it uses less digits than its factorization.

129189918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150600.

The product of its digits is 93312, while the sum is 48.

The square root of 129189918 is about 11366.1742904110. The cubic root of 129189918 is about 505.5252750978.

The spelling of 129189918 in words is "one hundred twenty-nine million, one hundred eighty-nine thousand, nine hundred eighteen".