21330582 has 48 divisors (see below), whose sum is σ = 53453232. Its totient is φ = 5624640.

The previous prime is 21330581. The next prime is 21330593. The reversal of 21330582 is 28503312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21330581) 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 23 ways as a sum of consecutive naturals, for example, 1032 + ... + 6612.

It is an arithmetic number, because the mean of its divisors is an integer number (1113609).

Almost surely, 2^21330582 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21330582, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26726616).

21330582 is an abundant number, since it is smaller than the sum of its proper divisors (32122650).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21330582 is a wasteful number, since it uses less digits than its factorization.

21330582 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5613 (or 5606 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 21330582 is about 4618.5043033432. The cubic root of 21330582 is about 277.3325863027.

Adding to 21330582 its reverse (28503312), we get a palindrome (49833894).

It can be divided in two parts, 21330 and 582, that added together give a palindrome (21912).

The spelling of 21330582 in words is "twenty-one million, three hundred thirty thousand, five hundred eighty-two".