20317497087 has 4 divisors (see below), whose sum is σ = 27089996120. Its totient is φ = 13544998056.

The previous prime is 20317497077. The next prime is 20317497139. The reversal of 20317497087 is 78079471302.

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

It is a de Polignac number, because none of the positive numbers 2^k-20317497087 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 (20317497077) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3386249512 + ... + 3386249517.

It is an arithmetic number, because the mean of its divisors is an integer number (6772499030).

Almost surely, 2^20317497087 is an apocalyptic number.

20317497087 is a deficient number, since it is larger than the sum of its proper divisors (6772499033).

20317497087 is an equidigital number, since it uses as much as digits as its factorization.

20317497087 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6772499032.

The product of its (nonzero) digits is 592704, while the sum is 48.

The spelling of 20317497087 in words is "twenty billion, three hundred seventeen million, four hundred ninety-seven thousand, eighty-seven".