21886656 has 112 divisors (see below), whose sum is σ = 64910208. Its totient is φ = 6451200.

The previous prime is 21886649. The next prime is 21886663. The reversal of 21886656 is 65668812.

It is an interprime number because it is at equal distance from previous prime (21886649) and next prime (21886663).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 90696 + ... + 90936.

Almost surely, 2^21886656 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 21886656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32455104).

21886656 is an abundant number, since it is smaller than the sum of its proper divisors (43023552).

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

21886656 is a wasteful number, since it uses less digits than its factorization.

21886656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310 (or 300 counting only the distinct ones).

The product of its digits is 138240, while the sum is 42.

The square root of 21886656 is about 4678.3176463340. The cubic root of 21886656 is about 279.7219007508.

The spelling of 21886656 in words is "twenty-one million, eight hundred eighty-six thousand, six hundred fifty-six".