20993184 has 36 divisors (see below), whose sum is σ = 59700186. Its totient is φ = 6997632.

The previous prime is 20993179. The next prime is 20993191. The reversal of 20993184 is 48139902.

It can be written as a sum of positive squares in only one way, i.e., 20903184 + 90000 = 4572^2 + 300^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 36159 + ... + 36734.

Almost surely, 2^20993184 is an apocalyptic number.

20993184 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20993184 is an abundant number, since it is smaller than the sum of its proper divisors (38707002).

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

20993184 is a wasteful number, since it uses less digits than its factorization.

20993184 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72909 (or 72898 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 20993184 is about 4581.8319480313. The cubic root of 20993184 is about 275.8625654761.

The spelling of 20993184 in words is "twenty million, nine hundred ninety-three thousand, one hundred eighty-four".