129978500 has 48 divisors (see below), whose sum is σ = 289965312. Its totient is φ = 50876000.

The previous prime is 129978491. The next prime is 129978503. The reversal of 129978500 is 5879921.

129978500 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (129978503) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20735 + ... + 26265.

It is an arithmetic number, because the mean of its divisors is an integer number (6040944).

Almost surely, 2^129978500 is an apocalyptic number.

129978500 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 129978500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144982656).

129978500 is an abundant number, since it is smaller than the sum of its proper divisors (159986812).

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

129978500 is a wasteful number, since it uses less digits than its factorization.

129978500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5597 (or 5585 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 41.

The square root of 129978500 is about 11400.8113746347. The cubic root of 129978500 is about 506.5517735407.

The spelling of 129978500 in words is "one hundred twenty-nine million, nine hundred seventy-eight thousand, five hundred".