21335243 has 8 divisors (see below), whose sum is σ = 21605280. Its totient is φ = 21067200.

The previous prime is 21335231. The next prime is 21335257. The reversal of 21335243 is 34253312.

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

It is a cyclic number.

It is not a de Polignac number, because 21335243 - 2⁶ = 21335179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21335263) 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, 34271 + ... + 34887.

It is an arithmetic number, because the mean of its divisors is an integer number (2700660).

Almost surely, 2^21335243 is an apocalyptic number.

21335243 is a deficient number, since it is larger than the sum of its proper divisors (270037).

21335243 is a wasteful number, since it uses less digits than its factorization.

21335243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 997.

The product of its digits is 2160, while the sum is 23.

The square root of 21335243 is about 4619.0088763716. The cubic root of 21335243 is about 277.3527850490.

Adding to 21335243 its reverse (34253312), we get a palindrome (55588555).

The spelling of 21335243 in words is "twenty-one million, three hundred thirty-five thousand, two hundred forty-three".