21089633 has 4 divisors (see below), whose sum is σ = 21105840. Its totient is φ = 21073428.

The previous prime is 21089623. The next prime is 21089659. The reversal of 21089633 is 33698012.

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 not a de Polignac number, because 21089633 - 2⁴ = 21089617 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21089633.

It is not an unprimeable number, because it can be changed into a prime (21089623) 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, 5963 + ... + 8816.

It is an arithmetic number, because the mean of its divisors is an integer number (5276460).

Almost surely, 2^21089633 is an apocalyptic number.

It is an amenable number.

21089633 is a deficient number, since it is larger than the sum of its proper divisors (16207).

21089633 is a wasteful number, since it uses less digits than its factorization.

21089633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16206.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 21089633 is about 4592.3450436569. The cubic root of 21089633 is about 276.2843853378.

The spelling of 21089633 in words is "twenty-one million, eighty-nine thousand, six hundred thirty-three".