20018711 has 4 divisors (see below), whose sum is σ = 20093400. Its totient is φ = 19944024.

The previous prime is 20018659. The next prime is 20018743. The reversal of 20018711 is 11781002.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20018711 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 (20015711) 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 3 ways as a sum of consecutive naturals, for example, 36941 + ... + 37478.

It is an arithmetic number, because the mean of its divisors is an integer number (5023350).

Almost surely, 2^20018711 is an apocalyptic number.

20018711 is a deficient number, since it is larger than the sum of its proper divisors (74689).

20018711 is an equidigital number, since it uses as much as digits as its factorization.

20018711 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74688.

The product of its (nonzero) digits is 112, while the sum is 20.

The square root of 20018711 is about 4474.2274193429. The cubic root of 20018711 is about 271.5263843887.

Adding to 20018711 its reverse (11781002), we get a palindrome (31799713).

The spelling of 20018711 in words is "twenty million, eighteen thousand, seven hundred eleven".