21398168 has 16 divisors (see below), whose sum is σ = 43769160. Its totient is φ = 9726400.

The previous prime is 21398141. The next prime is 21398171. The reversal of 21398168 is 86189312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121493 + ... + 121668.

Almost surely, 2^21398168 is an apocalyptic number.

It is an amenable number.

21398168 is an abundant number, since it is smaller than the sum of its proper divisors (22370992).

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

21398168 is a wasteful number, since it uses less digits than its factorization.

21398168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243178 (or 243174 counting only the distinct ones).

The product of its digits is 20736, while the sum is 38.

The square root of 21398168 is about 4625.8153875830. The cubic root of 21398168 is about 277.6251871385.

The spelling of 21398168 in words is "twenty-one million, three hundred ninety-eight thousand, one hundred sixty-eight".