20681056 has 48 divisors (see below), whose sum is σ = 45532368. Its totient is φ = 9164800.

The previous prime is 20681041. The next prime is 20681069. The reversal of 20681056 is 65018602.

It is a Smith number, since the sum of its digits (28) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13716 + ... + 15148.

It is an arithmetic number, because the mean of its divisors is an integer number (948591).

Almost surely, 2^20681056 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 20681056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22766184).

20681056 is an abundant number, since it is smaller than the sum of its proper divisors (24851312).

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

20681056 is a wasteful number, since it uses less digits than its factorization.

20681056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1495 (or 1487 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 20681056 is about 4547.6429059459. The cubic root of 20681056 is about 274.4885524250.

Adding to 20681056 its reverse (65018602), we get a palindrome (85699658).

The spelling of 20681056 in words is "twenty million, six hundred eighty-one thousand, fifty-six".