21221102011 has 4 divisors (see below), whose sum is σ = 21222063072. Its totient is φ = 21220140952.

The previous prime is 21221101963. The next prime is 21221102087. The reversal of 21221102011 is 11020112212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21221102011 - 2¹⁹ = 21220577723 is a prime.

It is a super-2 number, since 2×21221102011² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21221101982 and 21221102000.

It is not an unprimeable number, because it can be changed into a prime (21221102311) 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 3 ways as a sum of consecutive naturals, for example, 446611 + ... + 491836.

It is an arithmetic number, because the mean of its divisors is an integer number (5305515768).

Almost surely, 2^21221102011 is an apocalyptic number.

21221102011 is a deficient number, since it is larger than the sum of its proper divisors (961061).

21221102011 is an equidigital number, since it uses as much as digits as its factorization.

21221102011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 961060.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21221102011 its reverse (11020112212), we get a palindrome (32241214223).

The spelling of 21221102011 in words is "twenty-one billion, two hundred twenty-one million, one hundred two thousand, eleven".