20881228 has 24 divisors (see below), whose sum is σ = 39710720. Its totient is φ = 9570960.

The previous prime is 20881181. The next prime is 20881229. The reversal of 20881228 is 82218802.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a self number, because there is not a number n which added to its sum of digits gives 20881228.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20881229) 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, 2076 + ... + 6787.

Almost surely, 2^20881228 is an apocalyptic number.

It is an amenable number.

20881228 is a deficient number, since it is larger than the sum of its proper divisors (18829492).

20881228 is a wasteful number, since it uses less digits than its factorization.

20881228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8917 (or 8915 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 31.

The square root of 20881228 is about 4569.5982317924. The cubic root of 20881228 is about 275.3713023024.

The spelling of 20881228 in words is "twenty million, eight hundred eighty-one thousand, two hundred twenty-eight".