21122011221 has 16 divisors (see below), whose sum is σ = 28459773888. Its totient is φ = 13932864000.

The previous prime is 21122011217. The next prime is 21122011243. The reversal of 21122011221 is 12211022112.

It is not a de Polignac number, because 21122011221 - 2² = 21122011217 is a prime.

It is a super-2 number, since 2×21122011221² (a number of 21 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 21122011221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122011201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2128371 + ... + 2138271.

It is an arithmetic number, because the mean of its divisors is an integer number (1778735868).

Almost surely, 2^21122011221 is an apocalyptic number.

It is an amenable number.

21122011221 is a deficient number, since it is larger than the sum of its proper divisors (7337762667).

21122011221 is an equidigital number, since it uses as much as digits as its factorization.

21122011221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17332.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21122011221 its reverse (12211022112), we get a palindrome (33333033333).

The spelling of 21122011221 in words is "twenty-one billion, one hundred twenty-two million, eleven thousand, two hundred twenty-one".