21743443 has 4 divisors (see below), whose sum is σ = 22068040. Its totient is φ = 21418848.

The previous prime is 21743437. The next prime is 21743453. The reversal of 21743443 is 34434712.

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 21743443 - 2¹³ = 21735251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21743413) 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, 162198 + ... + 162331.

It is an arithmetic number, because the mean of its divisors is an integer number (5517010).

Almost surely, 2^21743443 is an apocalyptic number.

21743443 is a deficient number, since it is larger than the sum of its proper divisors (324597).

21743443 is an equidigital number, since it uses as much as digits as its factorization.

21743443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 324596.

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

The square root of 21743443 is about 4662.9864893649. The cubic root of 21743443 is about 279.1104550172.

It can be divided in two parts, 217 and 43443, that added together give a triangular number (43660 = T₂₉₅).

The spelling of 21743443 in words is "twenty-one million, seven hundred forty-three thousand, four hundred forty-three".