21645168 has 40 divisors (see below), whose sum is σ = 57222528. Its totient is φ = 7046592.

The previous prime is 21645167. The next prime is 21645181. The reversal of 21645168 is 86154612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21645167) 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, 3180 + ... + 7307.

Almost surely, 2^21645168 is an apocalyptic number.

It is an amenable number.

21645168 is an abundant number, since it is smaller than the sum of its proper divisors (35577360).

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

21645168 is a wasteful number, since it uses less digits than its factorization.

21645168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10541 (or 10535 counting only the distinct ones).

The product of its digits is 11520, while the sum is 33.

The square root of 21645168 is about 4652.4367808709. The cubic root of 21645168 is about 278.6893164235.

The spelling of 21645168 in words is "twenty-one million, six hundred forty-five thousand, one hundred sixty-eight".