16557228 has 18 divisors (see below), whose sum is σ = 41853084. Its totient is φ = 5519064.

The previous prime is 16557223. The next prime is 16557239. The reversal of 16557228 is 82275561.

It is a happy number.

16557228 is a `hidden beast` number, since 1 + 65 + 572 + 28 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 459923 = 16557228 / (1 + 6 + 5 + 5 + 7 + 2 + 2 + 8).

It is a junction number, because it is equal to n+sod(n) for n = 16557192 and 16557201.

It is not an unprimeable number, because it can be changed into a prime (16557223) 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 5 ways as a sum of consecutive naturals, for example, 229926 + ... + 229997.

Almost surely, 2^16557228 is an apocalyptic number.

16557228 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

16557228 is an abundant number, since it is smaller than the sum of its proper divisors (25295856).

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

16557228 is a wasteful number, since it uses less digits than its factorization.

16557228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459933 (or 459928 counting only the distinct ones).

The product of its digits is 33600, while the sum is 36.

The square root of 16557228 is about 4069.0573847023. The cubic root of 16557228 is about 254.8761567037.

It can be divided in two parts, 165572 and 28, that added together give a triangular number (165600 = T₅₇₅).

The spelling of 16557228 in words is "sixteen million, five hundred fifty-seven thousand, two hundred twenty-eight".