21344504 has 8 divisors (see below), whose sum is σ = 40020960. Its totient is φ = 10672248.

The previous prime is 21344473. The next prime is 21344507. The reversal of 21344504 is 40544312.

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 21344504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21344507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1334024 + ... + 1334039.

It is an arithmetic number, because the mean of its divisors is an integer number (5002620).

Almost surely, 2^21344504 is an apocalyptic number.

It is an amenable number.

21344504 is a deficient number, since it is larger than the sum of its proper divisors (18676456).

21344504 is a wasteful number, since it uses less digits than its factorization.

21344504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2668069 (or 2668065 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 21344504 is about 4620.0112553975. The cubic root of 21344504 is about 277.3929094664.

Adding to 21344504 its reverse (40544312), we get a palindrome (61888816).

The spelling of 21344504 in words is "twenty-one million, three hundred forty-four thousand, five hundred four".