21563343 has 6 divisors (see below), whose sum is σ = 31147064. Its totient is φ = 14375556.

The previous prime is 21563329. The next prime is 21563363. The reversal of 21563343 is 34336512.

It is a happy number.

21563343 is a `hidden beast` number, since 21 + 5 + 633 + 4 + 3 = 666.

It is not a de Polignac number, because 21563343 - 2²¹ = 19466191 is a prime.

It is a super-2 number, since 2×21563343² = 929955522671298, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21563303) 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 5 ways as a sum of consecutive naturals, for example, 1197955 + ... + 1197972.

Almost surely, 2^21563343 is an apocalyptic number.

21563343 is a deficient number, since it is larger than the sum of its proper divisors (9583721).

21563343 is a wasteful number, since it uses less digits than its factorization.

21563343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2395933 (or 2395930 counting only the distinct ones).

The product of its digits is 6480, while the sum is 27.

The square root of 21563343 is about 4643.6346755532. The cubic root of 21563343 is about 278.3376975503.

Adding to 21563343 its reverse (34336512), we get a palindrome (55899855).

The spelling of 21563343 in words is "twenty-one million, five hundred sixty-three thousand, three hundred forty-three".