21340444 has 12 divisors (see below), whose sum is σ = 38140704. Its totient is φ = 10443104.

The previous prime is 21340441. The next prime is 21340469. The reversal of 21340444 is 44404312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21340441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56569 + ... + 56944.

It is an arithmetic number, because the mean of its divisors is an integer number (3178392).

Almost surely, 2^21340444 is an apocalyptic number.

It is an amenable number.

21340444 is a deficient number, since it is larger than the sum of its proper divisors (16800260).

21340444 is a wasteful number, since it uses less digits than its factorization.

21340444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113564 (or 113562 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 22.

The square root of 21340444 is about 4619.5718416321. The cubic root of 21340444 is about 277.3753204479.

Adding to 21340444 its reverse (44404312), we get a palindrome (65744756).

The spelling of 21340444 in words is "twenty-one million, three hundred forty thousand, four hundred forty-four".