20684917 has 16 divisors (see below), whose sum is σ = 23748480. Its totient is φ = 17841600.

The previous prime is 20684899. The next prime is 20684929. The reversal of 20684917 is 71948602.

It is a cyclic number.

It is not a de Polignac number, because 20684917 - 2¹¹ = 20682869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20684947) 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, 18928 + ... + 19990.

It is an arithmetic number, because the mean of its divisors is an integer number (1484280).

Almost surely, 2^20684917 is an apocalyptic number.

It is an amenable number.

20684917 is a deficient number, since it is larger than the sum of its proper divisors (3063563).

20684917 is a wasteful number, since it uses less digits than its factorization.

20684917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1164.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 20684917 is about 4548.0673917610. The cubic root of 20684917 is about 274.5056330221.

The spelling of 20684917 in words is "twenty million, six hundred eighty-four thousand, nine hundred seventeen".