21789433 has 4 divisors (see below), whose sum is σ = 22296208. Its totient is φ = 21282660.

The previous prime is 21789421. The next prime is 21789463. The reversal of 21789433 is 33498712.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21789433 is a prime.

It is a super-2 number, since 2×21789433² = 949558780922978, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21789392 and 21789401.

It is not an unprimeable number, because it can be changed into a prime (21789463) 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, 253323 + ... + 253408.

It is an arithmetic number, because the mean of its divisors is an integer number (5574052).

Almost surely, 2^21789433 is an apocalyptic number.

It is an amenable number.

21789433 is a deficient number, since it is larger than the sum of its proper divisors (506775).

21789433 is an equidigital number, since it uses as much as digits as its factorization.

21789433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 506774.

The product of its digits is 36288, while the sum is 37.

The square root of 21789433 is about 4667.9152734385. The cubic root of 21789433 is about 279.3071005124.

It can be divided in two parts, 21789 and 433, that added together give a palindrome (22222).

The spelling of 21789433 in words is "twenty-one million, seven hundred eighty-nine thousand, four hundred thirty-three".