1638228 has 12 divisors (see below), whose sum is σ = 3822560. Its totient is φ = 546072.

The previous prime is 1638211. The next prime is 1638251. The reversal of 1638228 is 8228361.

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

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 1638195 and 1638204.

It is a congruent number.

It is an unprimeable number.

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, 68248 + ... + 68271.

2^1638228 is an apocalyptic number.

It is an amenable number.

1638228 is an abundant number, since it is smaller than the sum of its proper divisors (2184332).

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

1638228 is a wasteful number, since it uses less digits than its factorization.

1638228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136526 (or 136524 counting only the distinct ones).

The product of its digits is 4608, while the sum is 30.

The square root of 1638228 is about 1279.9328107366. The cubic root of 1638228 is about 117.8848824644.

The spelling of 1638228 in words is "one million, six hundred thirty-eight thousand, two hundred twenty-eight".