21404433 has 8 divisors (see below), whose sum is σ = 29023200. Its totient is φ = 14027648.

The previous prime is 21404417. The next prime is 21404437. The reversal of 21404433 is 33440412.

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 21404433 - 2⁴ = 21404417 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21404437) 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 7 ways as a sum of consecutive naturals, for example, 60288 + ... + 60641.

It is an arithmetic number, because the mean of its divisors is an integer number (3627900).

Almost surely, 2^21404433 is an apocalyptic number.

It is an amenable number.

21404433 is a deficient number, since it is larger than the sum of its proper divisors (7618767).

21404433 is a wasteful number, since it uses less digits than its factorization.

21404433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120991.

The product of its (nonzero) digits is 1152, while the sum is 21.

The square root of 21404433 is about 4626.4925159347. The cubic root of 21404433 is about 277.6522790540.

Adding to 21404433 its reverse (33440412), we get a palindrome (54844845).

The spelling of 21404433 in words is "twenty-one million, four hundred four thousand, four hundred thirty-three".