21089263 has 8 divisors (see below), whose sum is σ = 22752128. Its totient is φ = 19432224.

The previous prime is 21089213. The next prime is 21089273. The reversal of 21089263 is 36298012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21089263 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21089203) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8770 + ... + 10912.

It is an arithmetic number, because the mean of its divisors is an integer number (2844016).

Almost surely, 2^21089263 is an apocalyptic number.

21089263 is a deficient number, since it is larger than the sum of its proper divisors (1662865).

21089263 is a wasteful number, since it uses less digits than its factorization.

21089263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2913.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 21089263 is about 4592.3047590507. The cubic root of 21089263 is about 276.2827696021.

The spelling of 21089263 in words is "twenty-one million, eighty-nine thousand, two hundred sixty-three".