21445343 has 4 divisors (see below), whose sum is σ = 21796968. Its totient is φ = 21093720.

The previous prime is 21445331. The next prime is 21445349. The reversal of 21445343 is 34354412.

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 21445343 - 2⁴ = 21445327 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 (21445349) 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, 175721 + ... + 175842.

It is an arithmetic number, because the mean of its divisors is an integer number (5449242).

Almost surely, 2^21445343 is an apocalyptic number.

21445343 is a deficient number, since it is larger than the sum of its proper divisors (351625).

21445343 is an equidigital number, since it uses as much as digits as its factorization.

21445343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351624.

The product of its digits is 5760, while the sum is 26.

The square root of 21445343 is about 4630.9116812999. The cubic root of 21445343 is about 277.8290574780.

Adding to 21445343 its reverse (34354412), we get a palindrome (55799755).

The spelling of 21445343 in words is "twenty-one million, four hundred forty-five thousand, three hundred forty-three".