21042882 has 64 divisors (see below), whose sum is σ = 53913600. Its totient is φ = 5959440.

The previous prime is 21042877. The next prime is 21042883. The reversal of 21042882 is 28824012.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21042883) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 67507 + ... + 67817.

It is an arithmetic number, because the mean of its divisors is an integer number (842400).

Almost surely, 2^21042882 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21042882, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26956800).

21042882 is an abundant number, since it is smaller than the sum of its proper divisors (32870718).

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

21042882 is a wasteful number, since it uses less digits than its factorization.

21042882 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 508 (or 502 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 21042882 is about 4587.2521186436. The cubic root of 21042882 is about 276.0800807323.

Adding to 21042882 its reverse (28824012), we get a palindrome (49866894).

The spelling of 21042882 in words is "twenty-one million, forty-two thousand, eight hundred eighty-two".