28784280 has 64 divisors (see below), whose sum is σ = 98691840. Its totient is φ = 6579072.

The previous prime is 28784279. The next prime is 28784299. The reversal of 28784280 is 8248782.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16294 + ... + 17973.

It is an arithmetic number, because the mean of its divisors is an integer number (1542060).

Almost surely, 2^28784280 is an apocalyptic number.

28784280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28784280 is an abundant number, since it is smaller than the sum of its proper divisors (69907560).

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

28784280 is a wasteful number, since it uses less digits than its factorization.

28784280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34288 (or 34284 counting only the distinct ones).

The product of its (nonzero) digits is 57344, while the sum is 39.

The square root of 28784280 is about 5365.0983215594. The cubic root of 28784280 is about 306.4679925097.

The spelling of 28784280 in words is "twenty-eight million, seven hundred eighty-four thousand, two hundred eighty".