21839356 has 96 divisors (see below), whose sum is σ = 52157952. Its totient is φ = 7741440.

The previous prime is 21839329. The next prime is 21839357. The reversal of 21839356 is 65393812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21839357) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 225100 + ... + 225196.

It is an arithmetic number, because the mean of its divisors is an integer number (543312).

Almost surely, 2^21839356 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 21839356, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26078976).

21839356 is an abundant number, since it is smaller than the sum of its proper divisors (30318596).

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

21839356 is a wasteful number, since it uses less digits than its factorization.

21839356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179 (or 177 counting only the distinct ones).

The product of its digits is 38880, while the sum is 37.

The square root of 21839356 is about 4673.2596760719. The cubic root of 21839356 is about 279.5202498975.

The spelling of 21839356 in words is "twenty-one million, eight hundred thirty-nine thousand, three hundred fifty-six".