21211343 has 4 divisors (see below), whose sum is σ = 21399168. Its totient is φ = 21023520.

The previous prime is 21211339. The next prime is 21211363. The reversal of 21211343 is 34311212.

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

It is a cyclic number.

It is not a de Polignac number, because 21211343 - 2² = 21211339 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 (21211363) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93743 + ... + 93968.

It is an arithmetic number, because the mean of its divisors is an integer number (5349792).

Almost surely, 2^21211343 is an apocalyptic number.

21211343 is a deficient number, since it is larger than the sum of its proper divisors (187825).

21211343 is a wasteful number, since it uses less digits than its factorization.

21211343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187824.

The product of its digits is 144, while the sum is 17.

The square root of 21211343 is about 4605.5773796561. The cubic root of 21211343 is about 276.8148527940.

Adding to 21211343 its reverse (34311212), we get a palindrome (55522555).

The spelling of 21211343 in words is "twenty-one million, two hundred eleven thousand, three hundred forty-three".