28279220 has 24 divisors (see below), whose sum is σ = 62512800. Its totient is φ = 10716192.

The previous prime is 28279187. The next prime is 28279241. The reversal of 28279220 is 2297282.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36830 + ... + 37589.

It is an arithmetic number, because the mean of its divisors is an integer number (2604700).

Almost surely, 2^28279220 is an apocalyptic number.

28279220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28279220 is an abundant number, since it is smaller than the sum of its proper divisors (34233580).

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

28279220 is a wasteful number, since it uses less digits than its factorization.

28279220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74447 (or 74445 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 28279220 is about 5317.8209823197. The cubic root of 28279220 is about 304.6649370713.

The spelling of 28279220 in words is "twenty-eight million, two hundred seventy-nine thousand, two hundred twenty".