21153244 has 12 divisors (see below), whose sum is σ = 42306544. Its totient is φ = 9065664.

The previous prime is 21153227. The next prime is 21153257. The reversal of 21153244 is 44235112.

21153244 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 377709 + ... + 377764.

Almost surely, 2^21153244 is an apocalyptic number.

It is an amenable number.

21153244 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21153244 is a wasteful number, since it uses less digits than its factorization.

21153244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 755484 (or 755482 counting only the distinct ones).

The product of its digits is 960, while the sum is 22.

The square root of 21153244 is about 4599.2655935486. The cubic root of 21153244 is about 276.5618848061.

Adding to 21153244 its reverse (44235112), we get a palindrome (65388356).

The spelling of 21153244 in words is "twenty-one million, one hundred fifty-three thousand, two hundred forty-four".