221200209 has 12 divisors (see below), whose sum is σ = 338306436. Its totient is φ = 138792192.

The previous prime is 221200193. The next prime is 221200211. The reversal of 221200209 is 902002122.

It can be written as a sum of positive squares in 2 ways, for example, as 141491025 + 79709184 = 11895^2 + 8928^2 .

It is not a de Polignac number, because 221200209 - 2⁴ = 221200193 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221200191 and 221200200.

It is not an unprimeable number, because it can be changed into a prime (221200249) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 722724 + ... + 723029.

It is an arithmetic number, because the mean of its divisors is an integer number (28192203).

Almost surely, 2^221200209 is an apocalyptic number.

It is an amenable number.

221200209 is a deficient number, since it is larger than the sum of its proper divisors (117106227).

221200209 is a wasteful number, since it uses less digits than its factorization.

221200209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1445776 (or 1445773 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 221200209 is about 14872.8009803130. The cubic root of 221200209 is about 604.7768764911.

The spelling of 221200209 in words is "two hundred twenty-one million, two hundred thousand, two hundred nine".