28989900 has 108 divisors (see below), whose sum is σ = 94311672. Its totient is φ = 7724160.

The previous prime is 28989889. The next prime is 28989901. The reversal of 28989900 is 998982.

It is a tau number, because it is divible by the number of its divisors (108).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (28989901) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 23704 + ... + 24896.

Almost surely, 2^28989900 is an apocalyptic number.

28989900 is a gapful number since it is divisible by the number (20) 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 28989900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47155836).

28989900 is an abundant number, since it is smaller than the sum of its proper divisors (65321772).

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

28989900 is a wasteful number, since it uses less digits than its factorization.

28989900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1222 (or 1203 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The square root of 28989900 is about 5384.2269640126. The cubic root of 28989900 is about 307.1960113007.

The spelling of 28989900 in words is "twenty-eight million, nine hundred eighty-nine thousand, nine hundred".