21745968 has 40 divisors (see below), whose sum is σ = 56358000. Its totient is φ = 7225344.

The previous prime is 21745967. The next prime is 21745979. The reversal of 21745968 is 86954712.

It is not an unprimeable number, because it can be changed into a prime (21745967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21048 + ... + 22056.

It is an arithmetic number, because the mean of its divisors is an integer number (1408950).

Almost surely, 2^21745968 is an apocalyptic number.

It is an amenable number.

21745968 is an abundant number, since it is smaller than the sum of its proper divisors (34612032).

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

21745968 is a wasteful number, since it uses less digits than its factorization.

21745968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1469 (or 1463 counting only the distinct ones).

The product of its digits is 120960, while the sum is 42.

The square root of 21745968 is about 4663.2572307348. The cubic root of 21745968 is about 279.1212586822.

The spelling of 21745968 in words is "twenty-one million, seven hundred forty-five thousand, nine hundred sixty-eight".