21440343 has 8 divisors (see below), whose sum is σ = 28723456. Its totient is φ = 14225400.

The previous prime is 21440317. The next prime is 21440351. The reversal of 21440343 is 34304412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21440343 - 2⁸ = 21440087 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 (21440843) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16303 + ... + 17568.

It is an arithmetic number, because the mean of its divisors is an integer number (3590432).

Almost surely, 2^21440343 is an apocalyptic number.

21440343 is a deficient number, since it is larger than the sum of its proper divisors (7283113).

21440343 is a wasteful number, since it uses less digits than its factorization.

21440343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34085.

The product of its (nonzero) digits is 1152, while the sum is 21.

The square root of 21440343 is about 4630.3717993267. The cubic root of 21440343 is about 277.8074637725.

Adding to 21440343 its reverse (34304412), we get a palindrome (55744755).

The spelling of 21440343 in words is "twenty-one million, four hundred forty thousand, three hundred forty-three".