21415343 has 4 divisors (see below), whose sum is σ = 21425808. Its totient is φ = 21404880.

The previous prime is 21415321. The next prime is 21415349. The reversal of 21415343 is 34351412.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21415343 - 2¹⁸ = 21153199 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 (21415349) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1046 + ... + 6627.

It is an arithmetic number, because the mean of its divisors is an integer number (5356452).

Almost surely, 2^21415343 is an apocalyptic number.

21415343 is a deficient number, since it is larger than the sum of its proper divisors (10465).

21415343 is an equidigital number, since it uses as much as digits as its factorization.

21415343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10464.

The product of its digits is 1440, while the sum is 23.

The square root of 21415343 is about 4627.6714446901. The cubic root of 21415343 is about 277.6994448575.

Adding to 21415343 its reverse (34351412), we get a palindrome (55766755).

The spelling of 21415343 in words is "twenty-one million, four hundred fifteen thousand, three hundred forty-three".