28256380 has 48 divisors (see below), whose sum is σ = 64393056. Its totient is φ = 10373120.

The previous prime is 28256377. The next prime is 28256381. The reversal of 28256380 is 8365282.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28256381) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12927 + ... + 14953.

It is an arithmetic number, because the mean of its divisors is an integer number (1341522).

Almost surely, 2^28256380 is an apocalyptic number.

28256380 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 28256380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32196528).

28256380 is an abundant number, since it is smaller than the sum of its proper divisors (36136676).

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

28256380 is a wasteful number, since it uses less digits than its factorization.

28256380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2094 (or 2092 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 34.

The square root of 28256380 is about 5315.6730523989. The cubic root of 28256380 is about 304.5828930665.

The spelling of 28256380 in words is "twenty-eight million, two hundred fifty-six thousand, three hundred eighty".