211221010209 has 64 divisors (see below), whose sum is σ = 327784071168. Its totient is φ = 119704622400.

The previous prime is 211221010201. The next prime is 211221010213. The reversal of 211221010209 is 902010122112.

It is not a de Polignac number, because 211221010209 - 2³ = 211221010201 is a prime.

It is a super-2 number, since 2×211221010209² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (211221010201) 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 63 ways as a sum of consecutive naturals, for example, 36775992 + ... + 36781734.

It is an arithmetic number, because the mean of its divisors is an integer number (5121626112).

Almost surely, 2^211221010209 is an apocalyptic number.

It is an amenable number.

211221010209 is a deficient number, since it is larger than the sum of its proper divisors (116563060959).

211221010209 is a wasteful number, since it uses less digits than its factorization.

211221010209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6858.

The product of its (nonzero) digits is 144, while the sum is 21.

The spelling of 211221010209 in words is "two hundred eleven billion, two hundred twenty-one million, ten thousand, two hundred nine".