87318163991 has 2 divisors, whose sum is σ = 87318163992. Its totient is φ = 87318163990.

The previous prime is 87318163981. The next prime is 87318164029. The reversal of 87318163991 is 19936181378.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 87318163991 - 2³⁰ = 86244422167 is a prime.

It is a super-5 number, since 5×87318163991⁵ (a number of 56 digits) contains 55555 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87318163951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43659081995 + 43659081996.

It is an arithmetic number, because the mean of its divisors is an integer number (43659081996).

Almost surely, 2^87318163991 is an apocalyptic number.

87318163991 is a deficient number, since it is larger than the sum of its proper divisors (1).

87318163991 is an equidigital number, since it uses as much as digits as its factorization.

87318163991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1959552, while the sum is 56.

The spelling of 87318163991 in words is "eighty-seven billion, three hundred eighteen million, one hundred sixty-three thousand, nine hundred ninety-one".