20021136 has 80 divisors (see below), whose sum is σ = 56395200. Its totient is φ = 6096384.

The previous prime is 20021093. The next prime is 20021137. The reversal of 20021136 is 63112002.

It is not an unprimeable number, because it can be changed into a prime (20021137) by changing a digit.

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, 26070 + ... + 26826.

It is an arithmetic number, because the mean of its divisors is an integer number (704940).

Almost surely, 2^20021136 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 20021136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28197600).

20021136 is an abundant number, since it is smaller than the sum of its proper divisors (36374064).

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

20021136 is a wasteful number, since it uses less digits than its factorization.

20021136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 816 (or 810 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 20021136 is about 4474.4984076430. The cubic root of 20021136 is about 271.5373478801.

Adding to 20021136 its reverse (63112002), we get a palindrome (83133138).

The spelling of 20021136 in words is "twenty million, twenty-one thousand, one hundred thirty-six".