212011221 has 16 divisors (see below), whose sum is σ = 293211648. Its totient is φ = 136152000.

The previous prime is 212011207. The next prime is 212011223. The reversal of 212011221 is 122110212.

It is not a de Polignac number, because 212011221 - 2⁹ = 212010709 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 212011197 and 212011206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212011223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1756 + ... + 20666.

It is an arithmetic number, because the mean of its divisors is an integer number (18325728).

Almost surely, 2^212011221 is an apocalyptic number.

It is an amenable number.

212011221 is a deficient number, since it is larger than the sum of its proper divisors (81200427).

212011221 is a wasteful number, since it uses less digits than its factorization.

212011221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19052.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 212011221 is about 14560.6051041844. The cubic root of 212011221 is about 596.2837156855.

Adding to 212011221 its reverse (122110212), we get a palindrome (334121433).

It can be divided in two parts, 21201 and 1221, that added together give a palindrome (22422).

The spelling of 212011221 in words is "two hundred twelve million, eleven thousand, two hundred twenty-one".