21868286 has 8 divisors (see below), whose sum is σ = 35784504. Its totient is φ = 9940120.

The previous prime is 21868247. The next prime is 21868289. The reversal of 21868286 is 68286812.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21868289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 496985 + ... + 497028.

It is an arithmetic number, because the mean of its divisors is an integer number (4473063).

Almost surely, 2^21868286 is an apocalyptic number.

21868286 is a deficient number, since it is larger than the sum of its proper divisors (13916218).

21868286 is a wasteful number, since it uses less digits than its factorization.

21868286 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 994026.

The product of its digits is 73728, while the sum is 41.

The square root of 21868286 is about 4676.3539215932. The cubic root of 21868286 is about 279.6436197256.

The spelling of 21868286 in words is "twenty-one million, eight hundred sixty-eight thousand, two hundred eighty-six".