18787327202491 has 2 divisors, whose sum is σ = 18787327202492. Its totient is φ = 18787327202490.

The previous prime is 18787327202489. The next prime is 18787327202569. The reversal of 18787327202491 is 19420272378781.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18787327202491 - 2¹ = 18787327202489 is a prime.

Together with 18787327202489, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18787327202401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9393663601245 + 9393663601246.

It is an arithmetic number, because the mean of its divisors is an integer number (9393663601246).

Almost surely, 2^{18787327202491} is an apocalyptic number.

18787327202491 is a deficient number, since it is larger than the sum of its proper divisors (1).

18787327202491 is an equidigital number, since it uses as much as digits as its factorization.

18787327202491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18966528, while the sum is 61.

The spelling of 18787327202491 in words is "eighteen trillion, seven hundred eighty-seven billion, three hundred twenty-seven million, two hundred two thousand, four hundred ninety-one".