21001111222111 has 8 divisors (see below), whose sum is σ = 22108191922800. Its totient is φ = 19894206427200.

The previous prime is 21001111222109. The next prime is 21001111222129. The reversal of 21001111222111 is 11122211110012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21001111222111 - 2¹ = 21001111222109 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 (21001111222411) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43731340 + ... + 44208961.

It is an arithmetic number, because the mean of its divisors is an integer number (2763523990350).

Almost surely, 2^{21001111222111} is an apocalyptic number.

21001111222111 is a deficient number, since it is larger than the sum of its proper divisors (1107080700689).

21001111222111 is a wasteful number, since it uses less digits than its factorization.

21001111222111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87952889.

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

Adding to 21001111222111 its reverse (11122211110012), we get a palindrome (32123322332123).

The spelling of 21001111222111 in words is "twenty-one trillion, one billion, one hundred eleven million, two hundred twenty-two thousand, one hundred eleven".