21000221221111 has 4 divisors (see below), whose sum is σ = 22909332241224. Its totient is φ = 19091110201000.

The previous prime is 21000221221099. The next prime is 21000221221123. The reversal of 21000221221111 is 11112212200012.

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

It is an interprime number because it is at equal distance from previous prime (21000221221099) and next prime (21000221221123).

It is a cyclic number.

It is not a de Polignac number, because 21000221221111 - 2⁵ = 21000221221079 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000221221141) 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, 954555510040 + ... + 954555510061.

It is an arithmetic number, because the mean of its divisors is an integer number (5727333060306).

Almost surely, 2^{21000221221111} is an apocalyptic number.

21000221221111 is a deficient number, since it is larger than the sum of its proper divisors (1909111020113).

21000221221111 is a wasteful number, since it uses less digits than its factorization.

21000221221111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1909111020112.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21000221221111 its reverse (11112212200012), we get a palindrome (32112433421123).

The spelling of 21000221221111 in words is "twenty-one trillion, two hundred twenty-one million, two hundred twenty-one thousand, one hundred eleven".