21240341 has 4 divisors (see below), whose sum is σ = 21258252. Its totient is φ = 21222432.

The previous prime is 21240313. The next prime is 21240377. The reversal of 21240341 is 14304212.

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

It can be written as a sum of positive squares in 2 ways, for example, as 8099716 + 13140625 = 2846^2 + 3625^2 .

It is a cyclic number.

It is not a de Polignac number, because 21240341 - 2¹⁴ = 21223957 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 (21240311) 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, 7040 + ... + 9593.

It is an arithmetic number, because the mean of its divisors is an integer number (5314563).

Almost surely, 2^21240341 is an apocalyptic number.

It is an amenable number.

21240341 is a deficient number, since it is larger than the sum of its proper divisors (17911).

21240341 is a wasteful number, since it uses less digits than its factorization.

21240341 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17910.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21240341 is about 4608.7244439215. The cubic root of 21240341 is about 276.9409397646.

Adding to 21240341 its reverse (14304212), we get a palindrome (35544553).

The spelling of 21240341 in words is "twenty-one million, two hundred forty thousand, three hundred forty-one".