221021000111111 has 4 divisors (see below), whose sum is σ = 226411756211424. Its totient is φ = 215630244010800.

The previous prime is 221021000111083. The next prime is 221021000111179. The reversal of 221021000111111 is 111111000120122.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221021000111111 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221021000117111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2695378050095 + ... + 2695378050176.

It is an arithmetic number, because the mean of its divisors is an integer number (56602939052856).

Almost surely, 2^{221021000111111} is an apocalyptic number.

221021000111111 is a deficient number, since it is larger than the sum of its proper divisors (5390756100313).

221021000111111 is an equidigital number, since it uses as much as digits as its factorization.

221021000111111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5390756100312.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 221021000111111 its reverse (111111000120122), we get a palindrome (332132000231233).

The spelling of 221021000111111 in words is "two hundred twenty-one trillion, twenty-one billion, one hundred eleven thousand, one hundred eleven".