21112010221 has 4 divisors (see below), whose sum is σ = 21116397852. Its totient is φ = 21107622592.

The previous prime is 21112010209. The next prime is 21112010233. The reversal of 21112010221 is 12201021112.

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

It is an interprime number because it is at equal distance from previous prime (21112010209) and next prime (21112010233).

It can be written as a sum of positive squares in 2 ways, for example, as 4596162025 + 16515848196 = 67795^2 + 128514^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112010221 - 2¹³ = 21112002029 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 (21112010261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2186590 + ... + 2196223.

It is an arithmetic number, because the mean of its divisors is an integer number (5279099463).

Almost surely, 2^21112010221 is an apocalyptic number.

It is an amenable number.

21112010221 is a deficient number, since it is larger than the sum of its proper divisors (4387631).

21112010221 is an equidigital number, since it uses as much as digits as its factorization.

21112010221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4387630.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21112010221 its reverse (12201021112), we get a palindrome (33313031333).

The spelling of 21112010221 in words is "twenty-one billion, one hundred twelve million, ten thousand, two hundred twenty-one".