211211222000021 has 4 divisors (see below), whose sum is σ = 223635411529452. Its totient is φ = 198787032470592.

The previous prime is 211211221999937. The next prime is 211211222000071. The reversal of 211211222000021 is 120000222112112.

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 147682527100900 + 63528694899121 = 12152470^2 + 7970489^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211211222000021 is a prime.

It is a super-2 number, since 2×211211222000021² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 12424189529413 = 211211222000021 / (2 + 1 + 1 + 2 + 1 + 1 + 2 + 2 + 2 + 0 + 0 + 0 + 0 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211211222000071) 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, 6212094764690 + ... + 6212094764723.

It is an arithmetic number, because the mean of its divisors is an integer number (55908852882363).

Almost surely, 2^{211211222000021} is an apocalyptic number.

It is an amenable number.

211211222000021 is a deficient number, since it is larger than the sum of its proper divisors (12424189529431).

211211222000021 is a wasteful number, since it uses less digits than its factorization.

211211222000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12424189529430.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 211211222000021 its reverse (120000222112112), we get a palindrome (331211444112133).

The spelling of 211211222000021 in words is "two hundred eleven trillion, two hundred eleven billion, two hundred twenty-two million, twenty-one", and thus it is an aban number.