21221111210011 has 4 divisors (see below), whose sum is σ = 21222928564432. Its totient is φ = 21219293855592.

The previous prime is 21221111209999. The next prime is 21221111210113. The reversal of 21221111210011 is 11001211112212.

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 21221111210011 - 2¹⁷ = 21221111078939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21221111210911) 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, 908659695 + ... + 908683048.

It is an arithmetic number, because the mean of its divisors is an integer number (5305732141108).

Almost surely, 2^{21221111210011} is an apocalyptic number.

21221111210011 is a deficient number, since it is larger than the sum of its proper divisors (1817354421).

21221111210011 is a wasteful number, since it uses less digits than its factorization.

21221111210011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1817354420.

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

Adding to 21221111210011 its reverse (11001211112212), we get a palindrome (32222322322223).

The spelling of 21221111210011 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred eleven million, two hundred ten thousand, eleven".