129981900 has 72 divisors (see below), whose sum is σ = 377656384. Its totient is φ = 34516800.

The previous prime is 129981899. The next prime is 129981913. The reversal of 129981900 is 9189921.

It is a happy number.

It is a super-2 number, since 2×129981900² = 33790588655220000, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 84135 + ... + 85665.

Almost surely, 2^129981900 is an apocalyptic number.

129981900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129981900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (188828192).

129981900 is an abundant number, since it is smaller than the sum of its proper divisors (247674484).

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

129981900 is a wasteful number, since it uses less digits than its factorization.

129981900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1831 (or 1824 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 39.

The square root of 129981900 is about 11400.9604858538. The cubic root of 129981900 is about 506.5561903250.

The spelling of 129981900 in words is "one hundred twenty-nine million, nine hundred eighty-one thousand, nine hundred".