217942228 has 12 divisors (see below), whose sum is σ = 435884512. Its totient is φ = 93403800.

The previous prime is 217942139. The next prime is 217942229. The reversal of 217942228 is 822249712.

217942228 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217942229) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3891798 + ... + 3891853.

Almost surely, 2^217942228 is an apocalyptic number.

217942228 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

217942228 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

217942228 is a wasteful number, since it uses less digits than its factorization.

217942228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7783662 (or 7783660 counting only the distinct ones).

The product of its digits is 32256, while the sum is 37.

The square root of 217942228 is about 14762.8665238158. The cubic root of 217942228 is about 601.7929958651.

The spelling of 217942228 in words is "two hundred seventeen million, nine hundred forty-two thousand, two hundred twenty-eight".