21133999 has 8 divisors (see below), whose sum is σ = 21600800. Its totient is φ = 20671200.

The previous prime is 21133979. The next prime is 21134021. The reversal of 21133999 is 99933112.

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 21133999 - 2⁵ = 21133967 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 (21133939) 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, 11269 + ... + 13009.

It is an arithmetic number, because the mean of its divisors is an integer number (2700100).

Almost surely, 2^21133999 is an apocalyptic number.

21133999 is a deficient number, since it is larger than the sum of its proper divisors (466801).

21133999 is a wasteful number, since it uses less digits than its factorization.

21133999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2001.

The product of its digits is 13122, while the sum is 37.

The square root of 21133999 is about 4597.1729356203. The cubic root of 21133999 is about 276.4779883222.

The spelling of 21133999 in words is "twenty-one million, one hundred thirty-three thousand, nine hundred ninety-nine".