20875209 has 8 divisors (see below), whose sum is σ = 27933792. Its totient is φ = 13866720.

The previous prime is 20875199. The next prime is 20875219. The reversal of 20875209 is 90257802.

It is an interprime number because it is at equal distance from previous prime (20875199) and next prime (20875219).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20875209 - 2⁴ = 20875193 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20875209.

It is not an unprimeable number, because it can be changed into a prime (20875219) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11539 + ... + 13224.

It is an arithmetic number, because the mean of its divisors is an integer number (3491724).

Almost surely, 2^20875209 is an apocalyptic number.

It is an amenable number.

20875209 is a deficient number, since it is larger than the sum of its proper divisors (7058583).

20875209 is a wasteful number, since it uses less digits than its factorization.

20875209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25047.

The product of its (nonzero) digits is 10080, while the sum is 33.

The square root of 20875209 is about 4568.9395925094. The cubic root of 20875209 is about 275.3448412286.

The spelling of 20875209 in words is "twenty million, eight hundred seventy-five thousand, two hundred nine".