21053242 has 24 divisors (see below), whose sum is σ = 38899764. Its totient is φ = 8491392.

The previous prime is 21053203. The next prime is 21053267. The reversal of 21053242 is 24235012.

It can be written as a sum of positive squares in 2 ways, for example, as 20894041 + 159201 = 4571^2 + 399^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4653 + ... + 7984.

Almost surely, 2^21053242 is an apocalyptic number.

21053242 is a deficient number, since it is larger than the sum of its proper divisors (17846522).

21053242 is a wasteful number, since it uses less digits than its factorization.

21053242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12670 (or 12663 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 21053242 is about 4588.3811960211. The cubic root of 21053242 is about 276.1253806169.

Adding to 21053242 its reverse (24235012), we get a palindrome (45288254).

The spelling of 21053242 in words is "twenty-one million, fifty-three thousand, two hundred forty-two".