28278280 has 32 divisors (see below), whose sum is σ = 63777600. Its totient is φ = 11284416.

The previous prime is 28278253. The next prime is 28278301. The reversal of 28278280 is 8287282.

It is a super-2 number, since 2×28278280² = 1599322239516800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32491 + ... + 33349.

It is an arithmetic number, because the mean of its divisors is an integer number (1993050).

Almost surely, 2^28278280 is an apocalyptic number.

28278280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28278280 is an abundant number, since it is smaller than the sum of its proper divisors (35499320).

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

28278280 is a wasteful number, since it uses less digits than its factorization.

28278280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1693 (or 1689 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 37.

The square root of 28278280 is about 5317.7325995202. The cubic root of 28278280 is about 304.6615613509.

The spelling of 28278280 in words is "twenty-eight million, two hundred seventy-eight thousand, two hundred eighty".