20870911 has 4 divisors (see below), whose sum is σ = 21969400. Its totient is φ = 19772424.

The previous prime is 20870909. The next prime is 20870939. The reversal of 20870911 is 11907802.

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 20870911 - 2¹ = 20870909 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20870911.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20880911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 549216 + ... + 549253.

It is an arithmetic number, because the mean of its divisors is an integer number (5492350).

Almost surely, 2^20870911 is an apocalyptic number.

20870911 is a deficient number, since it is larger than the sum of its proper divisors (1098489).

20870911 is a wasteful number, since it uses less digits than its factorization.

20870911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1098488.

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 20870911 is about 4568.4692184582. The cubic root of 20870911 is about 275.3259430009.

The spelling of 20870911 in words is "twenty million, eight hundred seventy thousand, nine hundred eleven".