28220620 has 24 divisors (see below), whose sum is σ = 59792544. Its totient is φ = 11187456.

The previous prime is 28220611. The next prime is 28220623. The reversal of 28220620 is 2602282.

It is a junction number, because it is equal to n+sod(n) for n = 28220591 and 28220600.

It is not an unprimeable number, because it can be changed into a prime (28220623) 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, 3984 + ... + 8503.

It is an arithmetic number, because the mean of its divisors is an integer number (2491356).

Almost surely, 2^28220620 is an apocalyptic number.

28220620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28220620 is an abundant number, since it is smaller than the sum of its proper divisors (31571924).

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

28220620 is a wasteful number, since it uses less digits than its factorization.

28220620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12609 (or 12607 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 28220620 is about 5312.3083494842. The cubic root of 28220620 is about 304.4543500348.

It can be divided in two parts, 282 and 20620, that added together give a palindrome (20902).

The spelling of 28220620 in words is "twenty-eight million, two hundred twenty thousand, six hundred twenty".