20311687 has 16 divisors (see below), whose sum is σ = 23496480. Its totient is φ = 17382400.

The previous prime is 20311679. The next prime is 20311693. The reversal of 20311687 is 78611302.

It is a cyclic number.

It is not a de Polignac number, because 20311687 - 2³ = 20311679 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 (20311607) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12303 + ... + 13855.

It is an arithmetic number, because the mean of its divisors is an integer number (1468530).

Almost surely, 2^20311687 is an apocalyptic number.

20311687 is a deficient number, since it is larger than the sum of its proper divisors (3184793).

20311687 is a wasteful number, since it uses less digits than its factorization.

20311687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1634.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 20311687 is about 4506.8488991756. The cubic root of 20311687 is about 272.8445805017.

Adding to 20311687 its reverse (78611302), we get a palindrome (98922989).

It can be divided in two parts, 203116 and 87, that added together give a triangular number (203203 = T₆₃₇).

The spelling of 20311687 in words is "twenty million, three hundred eleven thousand, six hundred eighty-seven".