21331659 has 8 divisors (see below), whose sum is σ = 28802560. Its totient is φ = 14040936.

The previous prime is 21331657. The next prime is 21331663. The reversal of 21331659 is 95613312.

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

It is not a de Polignac number, because 21331659 - 2¹ = 21331657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21331657) 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, 44767 + ... + 45240.

It is an arithmetic number, because the mean of its divisors is an integer number (3600320).

Almost surely, 2^21331659 is an apocalyptic number.

21331659 is a deficient number, since it is larger than the sum of its proper divisors (7470901).

21331659 is an equidigital number, since it uses as much as digits as its factorization.

21331659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90089.

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

The square root of 21331659 is about 4618.6208980604. The cubic root of 21331659 is about 277.3372538136.

The spelling of 21331659 in words is "twenty-one million, three hundred thirty-one thousand, six hundred fifty-nine".