28308100 has 72 divisors (see below), whose sum is σ = 66245760. Its totient is φ = 10465920.

The previous prime is 28308083. The next prime is 28308109. The reversal of 28308100 is 180382.

It is a super-2 number, since 2×28308100² = 1602697051220000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28308109) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 89142 + ... + 89458.

It is an arithmetic number, because the mean of its divisors is an integer number (920080).

Almost surely, 2^28308100 is an apocalyptic number.

28308100 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 28308100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33122880).

28308100 is an abundant number, since it is smaller than the sum of its proper divisors (37937660).

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

28308100 is a wasteful number, since it uses less digits than its factorization.

28308100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397 (or 390 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 28308100 is about 5320.5356873157. The cubic root of 28308100 is about 304.7686142574.

Adding to 28308100 its reverse (180382), we get a palindrome (28488482).

The spelling of 28308100 in words is "twenty-eight million, three hundred eight thousand, one hundred".