21425344 has 14 divisors (see below), whose sum is σ = 42516044. Its totient is φ = 10712640.

The previous prime is 21425333. The next prime is 21425347. The reversal of 21425344 is 44352412.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21425347) 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 as a sum of consecutive naturals, namely, 167322 + ... + 167449.

Almost surely, 2^21425344 is an apocalyptic number.

It is an amenable number.

21425344 is a deficient number, since it is larger than the sum of its proper divisors (21090700).

21425344 is an equidigital number, since it uses as much as digits as its factorization.

21425344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 334783 (or 334773 counting only the distinct ones).

The product of its digits is 3840, while the sum is 25.

The square root of 21425344 is about 4628.7518836075. The cubic root of 21425344 is about 277.7426668274.

Adding to 21425344 its reverse (44352412), we get a palindrome (65777756).

The spelling of 21425344 in words is "twenty-one million, four hundred twenty-five thousand, three hundred forty-four".