20280228 has 12 divisors (see below), whose sum is σ = 47320560. Its totient is φ = 6760072.

The previous prime is 20280217. The next prime is 20280229. The reversal of 20280228 is 82208202.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×20280228² = 822575295463968, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20280198 and 20280207.

It is not an unprimeable number, because it can be changed into a prime (20280229) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 844998 + ... + 845021.

It is an arithmetic number, because the mean of its divisors is an integer number (3943380).

Almost surely, 2^20280228 is an apocalyptic number.

It is an amenable number.

20280228 is an abundant number, since it is smaller than the sum of its proper divisors (27040332).

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

20280228 is a wasteful number, since it uses less digits than its factorization.

20280228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1690026 (or 1690024 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 24.

The square root of 20280228 is about 4503.3574141967. The cubic root of 20280228 is about 272.7036459936.

The spelling of 20280228 in words is "twenty million, two hundred eighty thousand, two hundred twenty-eight".