21236168 has 16 divisors (see below), whose sum is σ = 39874380. Its totient is φ = 10603008.

The previous prime is 21236161. The next prime is 21236219. The reversal of 21236168 is 86163212.

It can be written as a sum of positive squares in 2 ways, for example, as 18992164 + 2244004 = 4358^2 + 1498^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21236168.

It is not an unprimeable number, because it can be changed into a prime (21236161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6080 + ... + 8912.

Almost surely, 2^21236168 is an apocalyptic number.

It is an amenable number.

21236168 is a deficient number, since it is larger than the sum of its proper divisors (18638212).

21236168 is a wasteful number, since it uses less digits than its factorization.

21236168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3776 (or 3772 counting only the distinct ones).

The product of its digits is 3456, while the sum is 29.

The square root of 21236168 is about 4608.2716933792. The cubic root of 21236168 is about 276.9228021048.

The spelling of 21236168 in words is "twenty-one million, two hundred thirty-six thousand, one hundred sixty-eight".