28218732 has 24 divisors (see below), whose sum is σ = 65999472. Its totient is φ = 9384000.

The previous prime is 28218731. The next prime is 28218733. The reversal of 28218732 is 23781282.

It is an interprime number because it is at equal distance from previous prime (28218731) and next prime (28218733).

It is a junction number, because it is equal to n+sod(n) for n = 28218693 and 28218702.

It is not an unprimeable number, because it can be changed into a prime (28218731) 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, 2982 + ... + 8082.

It is an arithmetic number, because the mean of its divisors is an integer number (2749978).

Almost surely, 2^28218732 is an apocalyptic number.

It is an amenable number.

28218732 is an abundant number, since it is smaller than the sum of its proper divisors (37780740).

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

28218732 is a wasteful number, since it uses less digits than its factorization.

28218732 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5569 (or 5567 counting only the distinct ones).

The product of its digits is 10752, while the sum is 33.

The square root of 28218732 is about 5312.1306459838. The cubic root of 28218732 is about 304.4475604056.

The spelling of 28218732 in words is "twenty-eight million, two hundred eighteen thousand, seven hundred thirty-two".