21633338 has 4 divisors (see below), whose sum is σ = 32450010. Its totient is φ = 10816668.

The previous prime is 21633329. The next prime is 21633349. The reversal of 21633338 is 83333612.

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., 15547249 + 6086089 = 3943^2 + 2467^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21633338.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5408333 + ... + 5408336.

Almost surely, 2^21633338 is an apocalyptic number.

21633338 is a deficient number, since it is larger than the sum of its proper divisors (10816672).

21633338 is a wasteful number, since it uses less digits than its factorization.

21633338 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10816671.

The product of its digits is 7776, while the sum is 29.

The square root of 21633338 is about 4651.1652303482. The cubic root of 21633338 is about 278.6385353373.

The spelling of 21633338 in words is "twenty-one million, six hundred thirty-three thousand, three hundred thirty-eight".