20881164 has 12 divisors (see below), whose sum is σ = 48722744. Its totient is φ = 6960384.

The previous prime is 20881163. The next prime is 20881181. The reversal of 20881164 is 46118802.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (20881163) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 870037 + ... + 870060.

Almost surely, 2^20881164 is an apocalyptic number.

It is an amenable number.

20881164 is an abundant number, since it is smaller than the sum of its proper divisors (27841580).

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

20881164 is a wasteful number, since it uses less digits than its factorization.

20881164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1740104 (or 1740102 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 20881164 is about 4569.5912289832. The cubic root of 20881164 is about 275.3710209687.

Adding to 20881164 its reverse (46118802), we get a palindrome (66999966).

The spelling of 20881164 in words is "twenty million, eight hundred eighty-one thousand, one hundred sixty-four".