21144768 has 28 divisors (see below), whose sum is σ = 55946040. Its totient is φ = 7048192.

The previous prime is 21144763. The next prime is 21144769. The reversal of 21144768 is 86744112.

It is not an unprimeable number, because it can be changed into a prime (21144763) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54873 + ... + 55256.

Almost surely, 2^21144768 is an apocalyptic number.

It is an amenable number.

21144768 is an abundant number, since it is smaller than the sum of its proper divisors (34801272).

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

21144768 is a wasteful number, since it uses less digits than its factorization.

21144768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110144 (or 110134 counting only the distinct ones).

The product of its digits is 10752, while the sum is 33.

The square root of 21144768 is about 4598.3440497640. The cubic root of 21144768 is about 276.5249408792.

It can be divided in two parts, 21144 and 768, that added together give a palindrome (21912).

The spelling of 21144768 in words is "twenty-one million, one hundred forty-four thousand, seven hundred sixty-eight".