18636228 has 36 divisors (see below), whose sum is σ = 50733228. Its totient is φ = 5734080.

The previous prime is 18636223. The next prime is 18636229. The reversal of 18636228 is 82263681.

18636228 is a `hidden beast` number, since 18 + 636 + 2 + 2 + 8 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 7225344 + 11410884 = 2688^2 + 3378^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 18636192 and 18636201.

It is not an unprimeable number, because it can be changed into a prime (18636221) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19443 + ... + 20378.

Almost surely, 2^18636228 is an apocalyptic number.

18636228 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

18636228 is an abundant number, since it is smaller than the sum of its proper divisors (32097000).

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

18636228 is a wasteful number, since it uses less digits than its factorization.

18636228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39844 (or 39839 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 18636228 is about 4316.9697705682. The cubic root of 18636228 is about 265.1262149447.

The spelling of 18636228 in words is "eighteen million, six hundred thirty-six thousand, two hundred twenty-eight".