21863238 has 8 divisors (see below), whose sum is σ = 43726488. Its totient is φ = 7287744.

The previous prime is 21863227. The next prime is 21863267. The reversal of 21863238 is 83236812.

It is a sphenic number, since it is the product of 3 distinct primes.

21863238 is an admirable number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21863199 and 21863208.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1821931 + ... + 1821942.

It is an arithmetic number, because the mean of its divisors is an integer number (5465811).

Almost surely, 2^21863238 is an apocalyptic number.

21863238 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21863238 is a wasteful number, since it uses less digits than its factorization.

21863238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3643878.

The product of its digits is 13824, while the sum is 33.

The square root of 21863238 is about 4675.8141537063. The cubic root of 21863238 is about 279.6221007456.

The spelling of 21863238 in words is "twenty-one million, eight hundred sixty-three thousand, two hundred thirty-eight".