21384343 has 4 divisors (see below), whose sum is σ = 21734968. Its totient is φ = 21033720.

The previous prime is 21384313. The next prime is 21384347. The reversal of 21384343 is 34348312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21384343 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 (21384347) 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, 175221 + ... + 175342.

It is an arithmetic number, because the mean of its divisors is an integer number (5433742).

Almost surely, 2^21384343 is an apocalyptic number.

21384343 is a deficient number, since it is larger than the sum of its proper divisors (350625).

21384343 is an equidigital number, since it uses as much as digits as its factorization.

21384343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350624.

The product of its digits is 6912, while the sum is 28.

The square root of 21384343 is about 4624.3208149954. The cubic root of 21384343 is about 277.5653845875.

The spelling of 21384343 in words is "twenty-one million, three hundred eighty-four thousand, three hundred forty-three".