21550414422221 has 4 divisors (see below), whose sum is σ = 22132858055292. Its totient is φ = 20967970789152.

The previous prime is 21550414422193. The next prime is 21550414422259. The reversal of 21550414422221 is 12222441405512.

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 18733220019721 + 2817194402500 = 4328189^2 + 1678450^2 .

It is a cyclic number.

It is not a de Polignac number, because 21550414422221 - 2³⁰ = 21549340680397 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 (21550414422281) 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, 291221816480 + ... + 291221816553.

It is an arithmetic number, because the mean of its divisors is an integer number (5533214513823).

Almost surely, 2^{21550414422221} is an apocalyptic number.

It is an amenable number.

21550414422221 is a deficient number, since it is larger than the sum of its proper divisors (582443633071).

21550414422221 is an equidigital number, since it uses as much as digits as its factorization.

21550414422221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 582443633070.

The product of its (nonzero) digits is 51200, while the sum is 35.

Adding to 21550414422221 its reverse (12222441405512), we get a palindrome (33772855827733).

The spelling of 21550414422221 in words is "twenty-one trillion, five hundred fifty billion, four hundred fourteen million, four hundred twenty-two thousand, two hundred twenty-one".