21043110 has 128 divisors (see below), whose sum is σ = 60715008. Its totient is φ = 4646400.

The previous prime is 21043097. The next prime is 21043111. The reversal of 21043110 is 1134012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21043111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 678795 + ... + 678825.

It is an arithmetic number, because the mean of its divisors is an integer number (474336).

Almost surely, 2^21043110 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21043110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30357504).

21043110 is an abundant number, since it is smaller than the sum of its proper divisors (39671898).

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

21043110 is a wasteful number, since it uses less digits than its factorization.

21043110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91 (or 69 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 21043110 is about 4587.2769700553. The cubic root of 21043110 is about 276.0810778395.

Adding to 21043110 its reverse (1134012), we get a palindrome (22177122).

The spelling of 21043110 in words is "twenty-one million, forty-three thousand, one hundred ten".