21037343 has 4 divisors (see below), whose sum is σ = 21434328. Its totient is φ = 20640360.

The previous prime is 21037339. The next prime is 21037361. The reversal of 21037343 is 34373012.

It is a happy number.

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 21037343 - 2² = 21037339 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 (21037243) 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, 198413 + ... + 198518.

It is an arithmetic number, because the mean of its divisors is an integer number (5358582).

Almost surely, 2^21037343 is an apocalyptic number.

21037343 is a deficient number, since it is larger than the sum of its proper divisors (396985).

21037343 is an equidigital number, since it uses as much as digits as its factorization.

21037343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396984.

The product of its (nonzero) digits is 1512, while the sum is 23.

The square root of 21037343 is about 4586.6483405642. The cubic root of 21037343 is about 276.0558549353.

The spelling of 21037343 in words is "twenty-one million, thirty-seven thousand, three hundred forty-three".