21838868 has 12 divisors (see below), whose sum is σ = 39879840. Its totient is φ = 10444632.

The previous prime is 21838867. The next prime is 21838889. The reversal of 21838868 is 86883812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21838867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 118598 + ... + 118781.

It is an arithmetic number, because the mean of its divisors is an integer number (3323320).

Almost surely, 2^21838868 is an apocalyptic number.

It is an amenable number.

21838868 is a deficient number, since it is larger than the sum of its proper divisors (18040972).

21838868 is a wasteful number, since it uses less digits than its factorization.

21838868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 237406 (or 237404 counting only the distinct ones).

The product of its digits is 147456, while the sum is 44.

The square root of 21838868 is about 4673.2074638304. The cubic root of 21838868 is about 279.5181679237.

The spelling of 21838868 in words is "twenty-one million, eight hundred thirty-eight thousand, eight hundred sixty-eight".