21344525 has 12 divisors (see below), whose sum is σ = 26864352. Its totient is φ = 16819440.

The previous prime is 21344513. The next prime is 21344593. The reversal of 21344525 is 52544312.

It is a happy number.

It is not a de Polignac number, because 21344525 - 2¹⁰ = 21343501 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21344494 and 21344503.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 4697 + ... + 8046.

It is an arithmetic number, because the mean of its divisors is an integer number (2238696).

Almost surely, 2^21344525 is an apocalyptic number.

21344525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21344525 is a deficient number, since it is larger than the sum of its proper divisors (5519827).

21344525 is a wasteful number, since it uses less digits than its factorization.

21344525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12820 (or 12815 counting only the distinct ones).

The product of its digits is 4800, while the sum is 26.

The square root of 21344525 is about 4620.0135281187. The cubic root of 21344525 is about 277.3930004383.

Adding to 21344525 its reverse (52544312), we get a palindrome (73888837).

The spelling of 21344525 in words is "twenty-one million, three hundred forty-four thousand, five hundred twenty-five".