21101100221111 has 4 divisors (see below), whose sum is σ = 21147273307392. Its totient is φ = 21054927134832.

The previous prime is 21101100221093. The next prime is 21101100221137. The reversal of 21101100221111 is 11112200110112.

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-21101100221111 is a prime.

It is a super-4 number, since 4×21101100221111⁴ (a number of 54 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101100221141) 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, 23086542455 + ... + 23086543368.

It is an arithmetic number, because the mean of its divisors is an integer number (5286818326848).

Almost surely, 2^{21101100221111} is an apocalyptic number.

21101100221111 is a deficient number, since it is larger than the sum of its proper divisors (46173086281).

21101100221111 is an equidigital number, since it uses as much as digits as its factorization.

21101100221111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46173086280.

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

Adding to 21101100221111 its reverse (11112200110112), we get a palindrome (32213300331223).

The spelling of 21101100221111 in words is "twenty-one trillion, one hundred one billion, one hundred million, two hundred twenty-one thousand, one hundred eleven".