28647220 has 24 divisors (see below), whose sum is σ = 68753664. Its totient is φ = 9821856.

The previous prime is 28647209. The next prime is 28647221. The reversal of 28647220 is 2274682.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28647221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 102172 + ... + 102451.

It is an arithmetic number, because the mean of its divisors is an integer number (2864736).

Almost surely, 2^28647220 is an apocalyptic number.

28647220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28647220 is an abundant number, since it is smaller than the sum of its proper divisors (40106444).

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

28647220 is a wasteful number, since it uses less digits than its factorization.

28647220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204639 (or 204637 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 31.

The square root of 28647220 is about 5352.3097817671. The cubic root of 28647220 is about 305.9807896579.

The spelling of 28647220 in words is "twenty-eight million, six hundred forty-seven thousand, two hundred twenty".