28747220 has 24 divisors (see below), whose sum is σ = 61774944. Its totient is φ = 11231136.

The previous prime is 28747189. The next prime is 28747259. The reversal of 28747220 is 2274782.

It is a happy number.

It is a congruent number.

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, 15854 + ... + 17573.

It is an arithmetic number, because the mean of its divisors is an integer number (2573956).

Almost surely, 2^28747220 is an apocalyptic number.

28747220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28747220 is an abundant number, since it is smaller than the sum of its proper divisors (33027724).

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

28747220 is a wasteful number, since it uses less digits than its factorization.

28747220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33479 (or 33477 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 32.

The square root of 28747220 is about 5361.6434047781. The cubic root of 28747220 is about 306.3364093252.

The spelling of 28747220 in words is "twenty-eight million, seven hundred forty-seven thousand, two hundred twenty".