21583321 has 8 divisors (see below), whose sum is σ = 22544640. Its totient is φ = 20641968.

The previous prime is 21583267. The next prime is 21583327. The reversal of 21583321 is 12338512.

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 21583321 - 2¹³ = 21575129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21583327) 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 7 ways as a sum of consecutive naturals, for example, 2761 + ... + 7126.

It is an arithmetic number, because the mean of its divisors is an integer number (2818080).

Almost surely, 2^21583321 is an apocalyptic number.

It is an amenable number.

21583321 is a deficient number, since it is larger than the sum of its proper divisors (961319).

21583321 is an equidigital number, since it uses as much as digits as its factorization.

21583321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9983.

The product of its digits is 1440, while the sum is 25.

The square root of 21583321 is about 4645.7852942210. The cubic root of 21583321 is about 278.4236290952.

It can be divided in two parts, 21583 and 321, that added together give a square (21904 = 148²).

The spelling of 21583321 in words is "twenty-one million, five hundred eighty-three thousand, three hundred twenty-one".