21768748 has 6 divisors (see below), whose sum is σ = 38095316. Its totient is φ = 10884372.

The previous prime is 21768739. The next prime is 21768749. The reversal of 21768748 is 84786712.

It is not an unprimeable number, because it can be changed into a prime (21768749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2721090 + ... + 2721097.

Almost surely, 2^21768748 is an apocalyptic number.

It is an amenable number.

21768748 is a deficient number, since it is larger than the sum of its proper divisors (16326568).

21768748 is a wasteful number, since it uses less digits than its factorization.

21768748 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5442191 (or 5442189 counting only the distinct ones).

The product of its digits is 150528, while the sum is 43.

The square root of 21768748 is about 4665.6990901686. The cubic root of 21768748 is about 279.2186892085.

The spelling of 21768748 in words is "twenty-one million, seven hundred sixty-eight thousand, seven hundred forty-eight".