129210138 has 24 divisors (see below), whose sum is σ = 289610100. Its totient is φ = 41584704.

The previous prime is 129210121. The next prime is 129210161. The reversal of 129210138 is 831012921.

It can be written as a sum of positive squares in 2 ways, for example, as 127848249 + 1361889 = 11307^2 + 1167^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 123243 + ... + 124286.

Almost surely, 2^129210138 is an apocalyptic number.

129210138 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

129210138 is an abundant number, since it is smaller than the sum of its proper divisors (160399962).

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

129210138 is a wasteful number, since it uses less digits than its factorization.

129210138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247566 (or 247563 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 129210138 is about 11367.0637369551. The cubic root of 129210138 is about 505.5516476094.

The spelling of 129210138 in words is "one hundred twenty-nine million, two hundred ten thousand, one hundred thirty-eight".