20805084 has 18 divisors (see below), whose sum is σ = 52590720. Its totient is φ = 6935016.

The previous prime is 20805049. The next prime is 20805089. The reversal of 20805084 is 48050802.

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20805089) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 288924 + ... + 288995.

Almost surely, 2^20805084 is an apocalyptic number.

It is an amenable number.

20805084 is an abundant number, since it is smaller than the sum of its proper divisors (31785636).

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

20805084 is a wasteful number, since it uses less digits than its factorization.

20805084 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 577929 (or 577924 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 27.

The square root of 20805084 is about 4561.2590367134. The cubic root of 20805084 is about 275.0361781604.

Adding to 20805084 its reverse (48050802), we get a palindrome (68855886).

The spelling of 20805084 in words is "twenty million, eight hundred five thousand, eighty-four".