21847956 has 48 divisors (see below), whose sum is σ = 56193984. Its totient is φ = 6564096.

The previous prime is 21847939. The next prime is 21847961. The reversal of 21847956 is 65974812.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5080 + ... + 8336.

It is an arithmetic number, because the mean of its divisors is an integer number (1170708).

Almost surely, 2^21847956 is an apocalyptic number.

21847956 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21847956, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28096992).

21847956 is an abundant number, since it is smaller than the sum of its proper divisors (34346028).

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

21847956 is a wasteful number, since it uses less digits than its factorization.

21847956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3320 (or 3318 counting only the distinct ones).

The product of its digits is 120960, while the sum is 42.

The square root of 21847956 is about 4674.1797141317. The cubic root of 21847956 is about 279.5569353303.

The spelling of 21847956 in words is "twenty-one million, eight hundred forty-seven thousand, nine hundred fifty-six".