21365343 has 8 divisors (see below), whose sum is σ = 31652400. Its totient is φ = 14243544.

The previous prime is 21365303. The next prime is 21365347. The reversal of 21365343 is 34356312.

It is a happy number.

21365343 is a `hidden beast` number, since 2 + 1 + 3 + 653 + 4 + 3 = 666.

It is not a de Polignac number, because 21365343 - 2⁸ = 21365087 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 791309 = 21365343 / (2 + 1 + 3 + 6 + 5 + 3 + 4 + 3).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21365347) 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 7 ways as a sum of consecutive naturals, for example, 395628 + ... + 395681.

It is an arithmetic number, because the mean of its divisors is an integer number (3956550).

Almost surely, 2^21365343 is an apocalyptic number.

21365343 is a deficient number, since it is larger than the sum of its proper divisors (10287057).

21365343 is an equidigital number, since it uses as much as digits as its factorization.

21365343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 791318 (or 791312 counting only the distinct ones).

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

The square root of 21365343 is about 4622.2660027307. The cubic root of 21365343 is about 277.4831545655.

It can be divided in two parts, 213 and 65343, that added together give a palindrome (65556).

The spelling of 21365343 in words is "twenty-one million, three hundred sixty-five thousand, three hundred forty-three".