21753338 has 4 divisors (see below), whose sum is σ = 32630010. Its totient is φ = 10876668.

The previous prime is 21753337. The next prime is 21753341. The reversal of 21753338 is 83335712.

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

It can be written as a sum of positive squares in only one way, i.e., 16216729 + 5536609 = 4027^2 + 2353^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21753337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5438333 + ... + 5438336.

Almost surely, 2^21753338 is an apocalyptic number.

21753338 is a deficient number, since it is larger than the sum of its proper divisors (10876672).

21753338 is a wasteful number, since it uses less digits than its factorization.

21753338 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10876671.

The product of its digits is 15120, while the sum is 32.

The square root of 21753338 is about 4664.0473839789. The cubic root of 21753338 is about 279.1527877657.

The spelling of 21753338 in words is "twenty-one million, seven hundred fifty-three thousand, three hundred thirty-eight".