21682056 has 32 divisors (see below), whose sum is σ = 59133600. Its totient is φ = 6570240.

The previous prime is 21682039. The next prime is 21682057. The reversal of 21682056 is 65028612.

It is a super-2 number, since 2×21682056² = 940223104774272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21682057) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40801 + ... + 41328.

It is an arithmetic number, because the mean of its divisors is an integer number (1847925).

Almost surely, 2^21682056 is an apocalyptic number.

It is an amenable number.

21682056 is an abundant number, since it is smaller than the sum of its proper divisors (37451544).

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

21682056 is a wasteful number, since it uses less digits than its factorization.

21682056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82149 (or 82145 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 21682056 is about 4656.3994673997. The cubic root of 21682056 is about 278.8475419928.

It can be divided in two parts, 2168 and 2056, that added together give a palindrome (4224).

The spelling of 21682056 in words is "twenty-one million, six hundred eighty-two thousand, fifty-six".