211221111001221 has 24 divisors (see below), whose sum is σ = 315636497448480. Its totient is φ = 135950341345056.

The previous prime is 211221111001193. The next prime is 211221111001223. The reversal of 211221111001221 is 122100111122112.

It is a happy number.

211221111001221 is a `hidden beast` number, since 211 + 22 + 111 + 100 + 1 + 221 = 666.

It is not a de Polignac number, because 211221111001221 - 2⁵ = 211221111001189 is a prime.

It is a super-2 number, since 2×211221111001221² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 211221111001194 and 211221111001203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211221111001223) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19628091 + ... + 28420136.

It is an arithmetic number, because the mean of its divisors is an integer number (13151520727020).

Almost surely, 2^{211221111001221} is an apocalyptic number.

It is an amenable number.

211221111001221 is a deficient number, since it is larger than the sum of its proper divisors (104415386447259).

211221111001221 is a wasteful number, since it uses less digits than its factorization.

211221111001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48065105 (or 48065102 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 211221111001221 its reverse (122100111122112), we get a palindrome (333321222123333).

The spelling of 211221111001221 in words is "two hundred eleven trillion, two hundred twenty-one billion, one hundred eleven million, one thousand, two hundred twenty-one".