21447343 has 4 divisors (see below), whose sum is σ = 21460288. Its totient is φ = 21434400.

The previous prime is 21447341. The next prime is 21447359. The reversal of 21447343 is 34374412.

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 21447343 - 2¹ = 21447341 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 (21447341) 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, 3546 + ... + 7447.

It is an arithmetic number, because the mean of its divisors is an integer number (5365072).

Almost surely, 2^21447343 is an apocalyptic number.

21447343 is a deficient number, since it is larger than the sum of its proper divisors (12945).

21447343 is a wasteful number, since it uses less digits than its factorization.

21447343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12944.

The product of its digits is 8064, while the sum is 28.

The square root of 21447343 is about 4631.1276164666. The cubic root of 21447343 is about 277.8376940204.

The spelling of 21447343 in words is "twenty-one million, four hundred forty-seven thousand, three hundred forty-three".