21111100102221 has 16 divisors (see below), whose sum is σ = 29001848523648. Its totient is φ = 13649655384000.

The previous prime is 21111100102199. The next prime is 21111100102241. The reversal of 21111100102221 is 12220100111112.

It is a happy number.

It is not a de Polignac number, because 21111100102221 - 2¹⁵ = 21111100069453 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21111100102221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111100102241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 305737330 + ... + 305806371.

It is an arithmetic number, because the mean of its divisors is an integer number (1812615532728).

Almost surely, 2^{21111100102221} is an apocalyptic number.

It is an amenable number.

21111100102221 is a deficient number, since it is larger than the sum of its proper divisors (7890748421427).

21111100102221 is a wasteful number, since it uses less digits than its factorization.

21111100102221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 611544052.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21111100102221 its reverse (12220100111112), we get a palindrome (33331200213333).

The spelling of 21111100102221 in words is "twenty-one trillion, one hundred eleven billion, one hundred million, one hundred two thousand, two hundred twenty-one".