21859936 has 48 divisors (see below), whose sum is σ = 51335424. Its totient is φ = 8959104.

The previous prime is 21859927. The next prime is 21859949. The reversal of 21859936 is 63995812.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21859892 and 21859901.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 3031 + ... + 7273.

It is an arithmetic number, because the mean of its divisors is an integer number (1069488).

Almost surely, 2^21859936 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 21859936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25667712).

21859936 is an abundant number, since it is smaller than the sum of its proper divisors (29475488).

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

21859936 is a wasteful number, since it uses less digits than its factorization.

21859936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4283 (or 4275 counting only the distinct ones).

The product of its digits is 116640, while the sum is 43.

The square root of 21859936 is about 4675.4610467846. The cubic root of 21859936 is about 279.6080229489.

It can be divided in two parts, 2185 and 9936, that added together give a palindrome (12121).

The spelling of 21859936 in words is "twenty-one million, eight hundred fifty-nine thousand, nine hundred thirty-six".