21120111302221 has 4 divisors (see below), whose sum is σ = 21120127564572. Its totient is φ = 21120095039872.

The previous prime is 21120111302189. The next prime is 21120111302263. The reversal of 21120111302221 is 12220311102112.

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

It can be written as a sum of positive squares in 2 ways, for example, as 2339718988996 + 18780392313225 = 1529614^2 + 4333635^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120111302221 - 2⁵ = 21120111302189 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 (21120111302021) 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, 5996260 + ... + 8842813.

It is an arithmetic number, because the mean of its divisors is an integer number (5280031891143).

Almost surely, 2^{21120111302221} is an apocalyptic number.

It is an amenable number.

21120111302221 is a deficient number, since it is larger than the sum of its proper divisors (16262351).

21120111302221 is a wasteful number, since it uses less digits than its factorization.

21120111302221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16262350.

The product of its (nonzero) digits is 96, while the sum is 19.

Adding to 21120111302221 its reverse (12220311102112), we get a palindrome (33340422404333).

The spelling of 21120111302221 in words is "twenty-one trillion, one hundred twenty billion, one hundred eleven million, three hundred two thousand, two hundred twenty-one".