128921700 has 72 divisors (see below), whose sum is σ = 376413408. Its totient is φ = 34065920.

The previous prime is 128921687. The next prime is 128921711. The reversal of 128921700 is 7129821.

128921700 is nontrivially palindromic in base 11.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31999 + ... + 35801.

It is an arithmetic number, because the mean of its divisors is an integer number (5227964).

Almost surely, 2^128921700 is an apocalyptic number.

128921700 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 128921700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (188206704).

128921700 is an abundant number, since it is smaller than the sum of its proper divisors (247491708).

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

128921700 is a wasteful number, since it uses less digits than its factorization.

128921700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3933 (or 3926 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 128921700 is about 11354.3692030865. The cubic root of 128921700 is about 505.1751834793.

The spelling of 128921700 in words is "one hundred twenty-eight million, nine hundred twenty-one thousand, seven hundred".