211051221 has 16 divisors (see below), whose sum is σ = 296524800. Its totient is φ = 133154928.

The previous prime is 211051189. The next prime is 211051237. The reversal of 211051221 is 122150112.

It is not a de Polignac number, because 211051221 - 2⁵ = 211051189 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 211051221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211031221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 91140 + ... + 93426.

It is an arithmetic number, because the mean of its divisors is an integer number (18532800).

Almost surely, 2^211051221 is an apocalyptic number.

It is an amenable number.

211051221 is a deficient number, since it is larger than the sum of its proper divisors (85473579).

211051221 is a wasteful number, since it uses less digits than its factorization.

211051221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3928.

The product of its (nonzero) digits is 40, while the sum is 15.

The square root of 211051221 is about 14527.6020388776. The cubic root of 211051221 is about 595.3823505792.

The spelling of 211051221 in words is "two hundred eleven million, fifty-one thousand, two hundred twenty-one".