20111228 has 6 divisors (see below), whose sum is σ = 35194656. Its totient is φ = 10055612.

The previous prime is 20111213. The next prime is 20111243. The reversal of 20111228 is 82211102.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20111213) and next prime (20111243).

It is a super-2 number, since 2×20111228² = 808922983335968, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2513900 + ... + 2513907.

It is an arithmetic number, because the mean of its divisors is an integer number (5865776).

Almost surely, 2^20111228 is an apocalyptic number.

It is an amenable number.

20111228 is a deficient number, since it is larger than the sum of its proper divisors (15083428).

20111228 is a wasteful number, since it uses less digits than its factorization.

20111228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5027811 (or 5027809 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

The square root of 20111228 is about 4484.5543814297. The cubic root of 20111228 is about 271.9440304389.

The spelling of 20111228 in words is "twenty million, one hundred eleven thousand, two hundred twenty-eight".