20007856 has 40 divisors (see below), whose sum is σ = 42854400. Its totient is φ = 8973120.

The previous prime is 20007851. The next prime is 20007859. The reversal of 20007856 is 65870002.

It is not an unprimeable number, because it can be changed into a prime (20007851) by changing a digit.

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, 13185 + ... + 14623.

It is an arithmetic number, because the mean of its divisors is an integer number (1071360).

Almost surely, 2^20007856 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 20007856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21427200).

20007856 is an abundant number, since it is smaller than the sum of its proper divisors (22846544).

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

20007856 is a wasteful number, since it uses less digits than its factorization.

20007856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1537 (or 1531 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 20007856 is about 4473.0141962663. The cubic root of 20007856 is about 271.4772977817.

Adding to 20007856 its reverse (65870002), we get a palindrome (85877858).

The spelling of 20007856 in words is "twenty million, seven thousand, eight hundred fifty-six".