20684159 has 2 divisors, whose sum is σ = 20684160. Its totient is φ = 20684158.

The previous prime is 20684149. The next prime is 20684171. The reversal of 20684159 is 95148602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20684159 - 2⁴ = 20684143 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20684149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10342079 + 10342080.

It is an arithmetic number, because the mean of its divisors is an integer number (10342080).

Almost surely, 2^20684159 is an apocalyptic number.

20684159 is a deficient number, since it is larger than the sum of its proper divisors (1).

20684159 is an equidigital number, since it uses as much as digits as its factorization.

20684159 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 20684159 is about 4547.9840588991. The cubic root of 20684159 is about 274.5022798894.

The spelling of 20684159 in words is "twenty million, six hundred eighty-four thousand, one hundred fifty-nine".