211211021221021 has 2 divisors, whose sum is σ = 211211021221022. Its totient is φ = 211211021221020.

The previous prime is 211211021221003. The next prime is 211211021221061. The reversal of 211211021221021 is 120122120112112.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 190271290980996 + 20939730240025 = 13793886^2 + 4575995^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211211021221021 is a prime.

It is a super-2 number, since 2×211211021221021² (a number of 29 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 211211021221021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211211021221061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105605510610510 + 105605510610511.

It is an arithmetic number, because the mean of its divisors is an integer number (105605510610511).

Almost surely, 2^{211211021221021} is an apocalyptic number.

It is an amenable number.

211211021221021 is a deficient number, since it is larger than the sum of its proper divisors (1).

211211021221021 is an equidigital number, since it uses as much as digits as its factorization.

211211021221021 is an evil number, because the sum of its binary digits is even.

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

Adding to 211211021221021 its reverse (120122120112112), we get a palindrome (331333141333133).

The spelling of 211211021221021 in words is "two hundred eleven trillion, two hundred eleven billion, twenty-one million, two hundred twenty-one thousand, twenty-one".