28555920 has 120 divisors (see below), whose sum is σ = 101585016. Its totient is φ = 7163904.

The previous prime is 28555907. The next prime is 28555939. The reversal of 28555920 is 2955582.

28555920 is a `hidden beast` number, since 2 + 85 + 559 + 20 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 4112784 + 24443136 = 2028^2 + 4944^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11074 + ... + 13406.

Almost surely, 2^28555920 is an apocalyptic number.

28555920 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 28555920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50792508).

28555920 is an abundant number, since it is smaller than the sum of its proper divisors (73029096).

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

28555920 is a wasteful number, since it uses less digits than its factorization.

28555920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2369 (or 2360 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 36.

The square root of 28555920 is about 5343.7739473148. The cubic root of 28555920 is about 305.6553854643.

The spelling of 28555920 in words is "twenty-eight million, five hundred fifty-five thousand, nine hundred twenty".