28558440 has 128 divisors (see below), whose sum is σ = 98380800. Its totient is φ = 7361280.

The previous prime is 28558399. The next prime is 28558441. The reversal of 28558440 is 4485582.

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

It is a junction number, because it is equal to n+sod(n) for n = 28558395 and 28558404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28558441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 33054 + ... + 33906.

It is an arithmetic number, because the mean of its divisors is an integer number (768600).

Almost surely, 2^28558440 is an apocalyptic number.

28558440 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 28558440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49190400).

28558440 is an abundant number, since it is smaller than the sum of its proper divisors (69822360).

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

28558440 is a wasteful number, since it uses less digits than its factorization.

28558440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 904 (or 894 counting only the distinct ones).

The product of its (nonzero) digits is 51200, while the sum is 36.

The square root of 28558440 is about 5344.0097305301. The cubic root of 28558440 is about 305.6643763485.

The spelling of 28558440 in words is "twenty-eight million, five hundred fifty-eight thousand, four hundred forty".