28205100 has 324 divisors, whose sum is σ = 114058672. Its totient is φ = 5702400.

The previous prime is 28205087. The next prime is 28205147. The reversal of 28205100 is 150282.

28205100 = 148² + 149² + ... + 444².

28205100 = 100³ + 101³ + ... + 120³.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 762282 + ... + 762318.

Almost surely, 2^28205100 is an apocalyptic number.

28205100 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 28205100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (57029336).

28205100 is an abundant number, since it is smaller than the sum of its proper divisors (85853572).

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

28205100 is a wasteful number, since it uses less digits than its factorization.

28205100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86 (or 65 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 28205100 is about 5310.8473900123. The cubic root of 28205100 is about 304.3985279919.

Adding to 28205100 its reverse (150282), we get a palindrome (28355382).

The spelling of 28205100 in words is "twenty-eight million, two hundred five thousand, one hundred".