21838608 has 120 divisors (see below), whose sum is σ = 70682976. Its totient is φ = 6220800.

The previous prime is 21838603. The next prime is 21838627. The reversal of 21838608 is 80683812.

21838608 is a `hidden beast` number, since 2 + 18 + 38 + 608 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21838603) 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 23 ways as a sum of consecutive naturals, for example, 26523 + ... + 27333.

Almost surely, 2^21838608 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21838608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35341488).

21838608 is an abundant number, since it is smaller than the sum of its proper divisors (48844368).

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

21838608 is a wasteful number, since it uses less digits than its factorization.

21838608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 853 (or 844 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 21838608 is about 4673.1796455946. The cubic root of 21838608 is about 279.5170586627.

The spelling of 21838608 in words is "twenty-one million, eight hundred thirty-eight thousand, six hundred eight".