21353344 has 16 divisors (see below), whose sum is σ = 42540120. Its totient is φ = 10676608.

The previous prime is 21353281. The next prime is 21353347. The reversal of 21353344 is 44335312.

It is a tau number, because it is divible by the number of its divisors (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21353347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83284 + ... + 83539.

Almost surely, 2^21353344 is an apocalyptic number.

It is an amenable number.

21353344 is a deficient number, since it is larger than the sum of its proper divisors (21186776).

21353344 is an equidigital number, since it uses as much as digits as its factorization.

21353344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166837 (or 166825 counting only the distinct ones).

The product of its digits is 4320, while the sum is 25.

The square root of 21353344 is about 4620.9678639869. The cubic root of 21353344 is about 277.4311990244.

Adding to 21353344 its reverse (44335312), we get a palindrome (65688656).

The spelling of 21353344 in words is "twenty-one million, three hundred fifty-three thousand, three hundred forty-four".