21173168 has 10 divisors (see below), whose sum is σ = 41023044. Its totient is φ = 10586576.

The previous prime is 21173167. The next prime is 21173203. The reversal of 21173168 is 86137112.

It is a self number, because there is not a number n which added to its sum of digits gives 21173168.

It is not an unprimeable number, because it can be changed into a prime (21173167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 661646 + ... + 661677.

Almost surely, 2^21173168 is an apocalyptic number.

It is an amenable number.

21173168 is a deficient number, since it is larger than the sum of its proper divisors (19849876).

21173168 is a wasteful number, since it uses less digits than its factorization.

21173168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1323331 (or 1323325 counting only the distinct ones).

The product of its digits is 2016, while the sum is 29.

The square root of 21173168 is about 4601.4310817397. The cubic root of 21173168 is about 276.6486877238.

The spelling of 21173168 in words is "twenty-one million, one hundred seventy-three thousand, one hundred sixty-eight".