21101220221111 has 8 divisors (see below), whose sum is σ = 21508050219120. Its totient is φ = 20694712214592.

The previous prime is 21101220221101. The next prime is 21101220221161. The reversal of 21101220221111 is 11112202210112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21101220221111 is a prime.

It is a super-4 number, since 4×21101220221111⁴ (a number of 54 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21101220221111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101220221101) 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, 80365541 + ... + 80627678.

It is an arithmetic number, because the mean of its divisors is an integer number (2688506277390).

Almost surely, 2^{21101220221111} is an apocalyptic number.

21101220221111 is a deficient number, since it is larger than the sum of its proper divisors (406829998009).

21101220221111 is a wasteful number, since it uses less digits than its factorization.

21101220221111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160995745.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21101220221111 its reverse (11112202210112), we get a palindrome (32213422431223).

The spelling of 21101220221111 in words is "twenty-one trillion, one hundred one billion, two hundred twenty million, two hundred twenty-one thousand, one hundred eleven".