21382056 has 96 divisors (see below), whose sum is σ = 63685440. Its totient is φ = 6697728.

The previous prime is 21382037. The next prime is 21382057. The reversal of 21382056 is 65028312.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21382057) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 32725 + ... + 33371.

It is an arithmetic number, because the mean of its divisors is an integer number (663390).

Almost surely, 2^21382056 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 21382056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31842720).

21382056 is an abundant number, since it is smaller than the sum of its proper divisors (42303384).

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

21382056 is a wasteful number, since it uses less digits than its factorization.

21382056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 685 (or 669 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 21382056 is about 4624.0735288272. The cubic root of 21382056 is about 277.5554892688. Note that the first 3 decimals are identical.

The spelling of 21382056 in words is "twenty-one million, three hundred eighty-two thousand, fifty-six".