21375968 has 12 divisors (see below), whose sum is σ = 42084000. Its totient is φ = 10687968.

The previous prime is 21375961. The next prime is 21375971. The reversal of 21375968 is 86957312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21375961) 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 as a sum of consecutive naturals, namely, 333968 + ... + 334031.

It is an arithmetic number, because the mean of its divisors is an integer number (3507000).

Almost surely, 2^21375968 is an apocalyptic number.

It is an amenable number.

21375968 is a deficient number, since it is larger than the sum of its proper divisors (20708032).

21375968 is an equidigital number, since it uses as much as digits as its factorization.

21375968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 668009 (or 668001 counting only the distinct ones).

The product of its digits is 90720, while the sum is 41.

The square root of 21375968 is about 4623.4151879320. The cubic root of 21375968 is about 277.5291444649.

The spelling of 21375968 in words is "twenty-one million, three hundred seventy-five thousand, nine hundred sixty-eight".