21254168 has 16 divisors (see below), whose sum is σ = 42917280. Its totient is φ = 9809568.

The previous prime is 21254161. The next prime is 21254171. The reversal of 21254168 is 86145212.

It is a self number, because there is not a number n which added to its sum of digits gives 21254168.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21254161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102080 + ... + 102287.

It is an arithmetic number, because the mean of its divisors is an integer number (2682330).

Almost surely, 2^21254168 is an apocalyptic number.

It is an amenable number.

21254168 is an abundant number, since it is smaller than the sum of its proper divisors (21663112).

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

21254168 is a wasteful number, since it uses less digits than its factorization.

21254168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204386 (or 204382 counting only the distinct ones).

The product of its digits is 3840, while the sum is 29.

The square root of 21254168 is about 4610.2242895547. The cubic root of 21254168 is about 277.0010209053.

The spelling of 21254168 in words is "twenty-one million, two hundred fifty-four thousand, one hundred sixty-eight".