18971971159 has 2 divisors, whose sum is σ = 18971971160. Its totient is φ = 18971971158.

The previous prime is 18971971157. The next prime is 18971971163. The reversal of 18971971159 is 95117917981.

It is a weak prime.

It is an emirp because it is prime and its reverse (95117917981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18971971159 - 2¹ = 18971971157 is a prime.

Together with 18971971157, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18971971157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9485985579 + 9485985580.

It is an arithmetic number, because the mean of its divisors is an integer number (9485985580).

Almost surely, 2^18971971159 is an apocalyptic number.

18971971159 is a deficient number, since it is larger than the sum of its proper divisors (1).

18971971159 is an equidigital number, since it uses as much as digits as its factorization.

18971971159 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1428840, while the sum is 58.

The spelling of 18971971159 in words is "eighteen billion, nine hundred seventy-one million, nine hundred seventy-one thousand, one hundred fifty-nine".