20317680 has 60 divisors (see below), whose sum is σ = 68235960. Its totient is φ = 5417856.

The previous prime is 20317667. The next prime is 20317681. The reversal of 20317680 is 8671302.

It is a tau number, because it is divible by the number of its divisors (60).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20317681) 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 11 ways as a sum of consecutive naturals, for example, 13390 + ... + 14829.

It is an arithmetic number, because the mean of its divisors is an integer number (1137266).

Almost surely, 2^20317680 is an apocalyptic number.

20317680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20317680 is an abundant number, since it is smaller than the sum of its proper divisors (47918280).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20317680 is a wasteful number, since it uses less digits than its factorization.

20317680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28238 (or 28229 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 20317680 is about 4507.5137271006. The cubic root of 20317680 is about 272.8714122920.

Adding to 20317680 its reverse (8671302), we get a palindrome (28988982).

The spelling of 20317680 in words is "twenty million, three hundred seventeen thousand, six hundred eighty".