21112200221 has 6 divisors (see below), whose sum is σ = 24559090110. Its totient is φ = 18096171576.

The previous prime is 21112200217. The next prime is 21112200271. The reversal of 21112200221 is 12200221112.

It can be written as a sum of positive squares in only one way, i.e., 21107731225 + 4468996 = 145285^2 + 2114^2 .

It is not a de Polignac number, because 21112200221 - 2² = 21112200217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21112200196 and 21112200205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112200211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 215430566 + ... + 215430663.

It is an arithmetic number, because the mean of its divisors is an integer number (4093181685).

Almost surely, 2^21112200221 is an apocalyptic number.

It is an amenable number.

21112200221 is a deficient number, since it is larger than the sum of its proper divisors (3446889889).

21112200221 is an equidigital number, since it uses as much as digits as its factorization.

21112200221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430861243 (or 430861236 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21112200221 its reverse (12200221112), we get a palindrome (33312421333).

The spelling of 21112200221 in words is "twenty-one billion, one hundred twelve million, two hundred thousand, two hundred twenty-one".