21133659 has 4 divisors (see below), whose sum is σ = 28178216. Its totient is φ = 14089104.

The previous prime is 21133649. The next prime is 21133667. The reversal of 21133659 is 95633112.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21133659 - 2⁸ = 21133403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21133639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3522274 + ... + 3522279.

It is an arithmetic number, because the mean of its divisors is an integer number (7044554).

Almost surely, 2^21133659 is an apocalyptic number.

21133659 is a deficient number, since it is larger than the sum of its proper divisors (7044557).

21133659 is an equidigital number, since it uses as much as digits as its factorization.

21133659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7044556.

The product of its digits is 4860, while the sum is 30.

The square root of 21133659 is about 4597.1359562232. The cubic root of 21133659 is about 276.4765056714.

The spelling of 21133659 in words is "twenty-one million, one hundred thirty-three thousand, six hundred fifty-nine".