319857817987 has 2 divisors, whose sum is σ = 319857817988. Its totient is φ = 319857817986.

The previous prime is 319857817897. The next prime is 319857817997. The reversal of 319857817987 is 789718758913.

Together with previous prime (319857817897) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 319857817987 - 2²³ = 319849429379 is a prime.

It is not a weakly prime, because it can be changed into another prime (319857817997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159928908993 + 159928908994.

It is an arithmetic number, because the mean of its divisors is an integer number (159928908994).

Almost surely, 2^319857817987 is an apocalyptic number.

319857817987 is a deficient number, since it is larger than the sum of its proper divisors (1).

319857817987 is an equidigital number, since it uses as much as digits as its factorization.

319857817987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 213373440, while the sum is 73.

The spelling of 319857817987 in words is "three hundred nineteen billion, eight hundred fifty-seven million, eight hundred seventeen thousand, nine hundred eighty-seven".