20717175487 has 2 divisors, whose sum is σ = 20717175488. Its totient is φ = 20717175486.

The previous prime is 20717175431. The next prime is 20717175499. The reversal of 20717175487 is 78457171702.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20717175487 - 2⁷ = 20717175359 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20717175487.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20717175187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10358587743 + 10358587744.

It is an arithmetic number, because the mean of its divisors is an integer number (10358587744).

Almost surely, 2^20717175487 is an apocalyptic number.

20717175487 is a deficient number, since it is larger than the sum of its proper divisors (1).

20717175487 is an equidigital number, since it uses as much as digits as its factorization.

20717175487 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768320, while the sum is 49.

The spelling of 20717175487 in words is "twenty billion, seven hundred seventeen million, one hundred seventy-five thousand, four hundred eighty-seven".