21534343 has 4 divisors (see below), whose sum is σ = 21829408. Its totient is φ = 21239280.

The previous prime is 21534329. The next prime is 21534349. The reversal of 21534343 is 34343512.

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 21534343 - 2²¹ = 19437191 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 (21534349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 147423 + ... + 147568.

It is an arithmetic number, because the mean of its divisors is an integer number (5457352).

Almost surely, 2^21534343 is an apocalyptic number.

21534343 is a deficient number, since it is larger than the sum of its proper divisors (295065).

21534343 is an equidigital number, since it uses as much as digits as its factorization.

21534343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295064.

The product of its digits is 4320, while the sum is 25.

The square root of 21534343 is about 4640.5110709921. The cubic root of 21534343 is about 278.2128651058.

Adding to 21534343 its reverse (34343512), we get a palindrome (55877855).

The spelling of 21534343 in words is "twenty-one million, five hundred thirty-four thousand, three hundred forty-three".