28187173717 has 2 divisors, whose sum is σ = 28187173718. Its totient is φ = 28187173716.

The previous prime is 28187173687. The next prime is 28187173733. The reversal of 28187173717 is 71737178182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21734425476 + 6452748241 = 147426^2 + 80329^2 .

It is a cyclic number.

It is not a de Polignac number, because 28187173717 - 2⁷ = 28187173589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28187173757) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14093586858 + 14093586859.

It is an arithmetic number, because the mean of its divisors is an integer number (14093586859).

Almost surely, 2^28187173717 is an apocalyptic number.

It is an amenable number.

28187173717 is a deficient number, since it is larger than the sum of its proper divisors (1).

28187173717 is an equidigital number, since it uses as much as digits as its factorization.

28187173717 is an evil number, because the sum of its binary digits is even.

The product of its digits is 921984, while the sum is 52.

The spelling of 28187173717 in words is "twenty-eight billion, one hundred eighty-seven million, one hundred seventy-three thousand, seven hundred seventeen".