21133642 has 8 divisors (see below), whose sum is σ = 33078816. Its totient is φ = 10107372.

The previous prime is 21133639. The next prime is 21133649. The reversal of 21133642 is 24633112.

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

It is not an unprimeable number, because it can be changed into a prime (21133649) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 229668 + ... + 229759.

It is an arithmetic number, because the mean of its divisors is an integer number (4134852).

Almost surely, 2^21133642 is an apocalyptic number.

21133642 is a deficient number, since it is larger than the sum of its proper divisors (11945174).

21133642 is a wasteful number, since it uses less digits than its factorization.

21133642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459452.

The product of its digits is 864, while the sum is 22.

The square root of 21133642 is about 4597.1341072455. The cubic root of 21133642 is about 276.4764315384.

Adding to 21133642 its reverse (24633112), we get a palindrome (45766754).

The spelling of 21133642 in words is "twenty-one million, one hundred thirty-three thousand, six hundred forty-two".