28704280 has 64 divisors (see below), whose sum is σ = 71344800. Its totient is φ = 10306560.

The previous prime is 28704271. The next prime is 28704281. The reversal of 28704280 is 8240782.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28704281) 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, 38794 + ... + 39526.

Almost surely, 2^28704280 is an apocalyptic number.

28704280 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 28704280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35672400).

28704280 is an abundant number, since it is smaller than the sum of its proper divisors (42640520).

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

28704280 is a wasteful number, since it uses less digits than its factorization.

28704280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 844 (or 840 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 31.

The square root of 28704280 is about 5357.6375390651. The cubic root of 28704280 is about 306.1838074352.

The spelling of 28704280 in words is "twenty-eight million, seven hundred four thousand, two hundred eighty".