222001820 has 24 divisors (see below), whose sum is σ = 473164944. Its totient is φ = 87474816.

The previous prime is 222001817. The next prime is 222001853. The reversal of 222001820 is 28100222.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81497 + ... + 84176.

It is an arithmetic number, because the mean of its divisors is an integer number (19715206).

Almost surely, 2^222001820 is an apocalyptic number.

222001820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

222001820 is an abundant number, since it is smaller than the sum of its proper divisors (251163124).

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

222001820 is a wasteful number, since it uses less digits than its factorization.

222001820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165749 (or 165747 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 222001820 is about 14899.7255008272. The cubic root of 222001820 is about 605.5065493296.

The spelling of 222001820 in words is "two hundred twenty-two million, one thousand, eight hundred twenty".