211222009 has 4 divisors (see below), whose sum is σ = 213595380. Its totient is φ = 208848640.

The previous prime is 211221979. The next prime is 211222019. The reversal of 211222009 is 900222112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 146773225 + 64448784 = 12115^2 + 8028^2 .

It is a cyclic number.

It is not a de Polignac number, because 211222009 - 2⁹ = 211221497 is a prime.

It is a super-2 number, since 2×211222009² = 89229474171992162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (211222019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1186552 + ... + 1186729.

It is an arithmetic number, because the mean of its divisors is an integer number (53398845).

Almost surely, 2^211222009 is an apocalyptic number.

It is an amenable number.

211222009 is a deficient number, since it is larger than the sum of its proper divisors (2373371).

211222009 is an equidigital number, since it uses as much as digits as its factorization.

211222009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2373370.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 211222009 is about 14533.4789021762. The cubic root of 211222009 is about 595.5429067770.

The spelling of 211222009 in words is "two hundred eleven million, two hundred twenty-two thousand, nine".