211221211212001 has 4 divisors (see below), whose sum is σ = 211237517965572. Its totient is φ = 211204904458432.

The previous prime is 211221211211893. The next prime is 211221211212029. The reversal of 211221211212001 is 100212112122112.

It is a happy number.

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 65892182760000 + 145329028452001 = 8117400^2 + 12055249^2 .

It is a cyclic number.

It is not a de Polignac number, because 211221211212001 - 2²¹ = 211221209114849 is a prime.

It is a super-2 number, since 2×211221211212001² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 211221211212001.

It is not an unprimeable number, because it can be changed into a prime (211221211212031) 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, 8153357356 + ... + 8153383261.

It is an arithmetic number, because the mean of its divisors is an integer number (52809379491393).

Almost surely, 2^{211221211212001} is an apocalyptic number.

It is an amenable number.

211221211212001 is a deficient number, since it is larger than the sum of its proper divisors (16306753571).

211221211212001 is a wasteful number, since it uses less digits than its factorization.

211221211212001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16306753570.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 211221211212001 its reverse (100212112122112), we get a palindrome (311433323334113).

The spelling of 211221211212001 in words is "two hundred eleven trillion, two hundred twenty-one billion, two hundred eleven million, two hundred twelve thousand, one".