20908159 has 4 divisors (see below), whose sum is σ = 21629160. Its totient is φ = 20187160.

The previous prime is 20908157. The next prime is 20908163. The reversal of 20908159 is 95180902.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20908159 - 2¹ = 20908157 is a prime.

It is a super-2 number, since 2×20908159² = 874302225538562, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20908157) 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, 360457 + ... + 360514.

It is an arithmetic number, because the mean of its divisors is an integer number (5407290).

Almost surely, 2^20908159 is an apocalyptic number.

20908159 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

20908159 is a deficient number, since it is larger than the sum of its proper divisors (721001).

20908159 is an equidigital number, since it uses as much as digits as its factorization.

20908159 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 721000.

The product of its (nonzero) digits is 6480, while the sum is 34.

The square root of 20908159 is about 4572.5440402472. The cubic root of 20908159 is about 275.4896356785.

The spelling of 20908159 in words is "twenty million, nine hundred eight thousand, one hundred fifty-nine".