21838870 has 16 divisors (see below), whose sum is σ = 39382848. Its totient is φ = 8719360.

The previous prime is 21838867. The next prime is 21838889. The reversal of 21838870 is 7883812.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4707 + ... + 8113.

It is an arithmetic number, because the mean of its divisors is an integer number (2461428).

Almost surely, 2^21838870 is an apocalyptic number.

21838870 is a deficient number, since it is larger than the sum of its proper divisors (17543978).

21838870 is a wasteful number, since it uses less digits than its factorization.

21838870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4055.

The product of its (nonzero) digits is 21504, while the sum is 37.

The square root of 21838870 is about 4673.2076778162. The cubic root of 21838870 is about 279.5181764565.

The spelling of 21838870 in words is "twenty-one million, eight hundred thirty-eight thousand, eight hundred seventy".