21144748 has 12 divisors (see below), whose sum is σ = 37449720. Its totient is φ = 10444832.

The previous prime is 21144743. The next prime is 21144763. The reversal of 21144748 is 84744112.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21144743) 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, 31513 + ... + 32176.

It is an arithmetic number, because the mean of its divisors is an integer number (3120810).

Almost surely, 2^21144748 is an apocalyptic number.

It is an amenable number.

21144748 is a deficient number, since it is larger than the sum of its proper divisors (16304972).

21144748 is a wasteful number, since it uses less digits than its factorization.

21144748 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63776 (or 63774 counting only the distinct ones).

The product of its digits is 7168, while the sum is 31.

The square root of 21144748 is about 4598.3418750676. The cubic root of 21144748 is about 276.5248536945.

The spelling of 21144748 in words is "twenty-one million, one hundred forty-four thousand, seven hundred forty-eight".