21122011020221 has 4 divisors (see below), whose sum is σ = 22040359325472. Its totient is φ = 20203662714972.

The previous prime is 21122011020199. The next prime is 21122011020223. The reversal of 21122011020221 is 12202011022112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21122011020221 - 2¹⁸ = 21122010758077 is a prime.

It is a super-2 number, since 2×21122011020221² (a number of 27 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 21122011020221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122011020223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 459174152591 + ... + 459174152636.

It is an arithmetic number, because the mean of its divisors is an integer number (5510089831368).

Almost surely, 2^{21122011020221} is an apocalyptic number.

It is an amenable number.

21122011020221 is a deficient number, since it is larger than the sum of its proper divisors (918348305251).

21122011020221 is an equidigital number, since it uses as much as digits as its factorization.

21122011020221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 918348305250.

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

Adding to 21122011020221 its reverse (12202011022112), we get a palindrome (33324022042333).

The spelling of 21122011020221 in words is "twenty-one trillion, one hundred twenty-two billion, eleven million, twenty thousand, two hundred twenty-one".