20986911 has 16 divisors (see below), whose sum is σ = 33918720. Its totient is φ = 12719160.

The previous prime is 20986897. The next prime is 20986913. The reversal of 20986911 is 11968902.

It is not a de Polignac number, because 20986911 - 2¹¹ = 20984863 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20986913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35035 + ... + 35628.

It is an arithmetic number, because the mean of its divisors is an integer number (2119920).

Almost surely, 2^20986911 is an apocalyptic number.

20986911 is a deficient number, since it is larger than the sum of its proper divisors (12931809).

20986911 is a wasteful number, since it uses less digits than its factorization.

20986911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70683 (or 70677 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 20986911 is about 4581.1473453710. The cubic root of 20986911 is about 275.8350857909.

Subtracting from 20986911 its reverse (11968902), we obtain a square (9018009 = 3003²).

It can be divided in two parts, 2098 and 6911, that added together give a palindrome (9009).

The spelling of 20986911 in words is "twenty million, nine hundred eighty-six thousand, nine hundred eleven".