166743743987 has 2 divisors, whose sum is σ = 166743743988. Its totient is φ = 166743743986.

The previous prime is 166743743927. The next prime is 166743744007. The reversal of 166743743987 is 789347347661.

It is a strong prime.

It is an emirp because it is prime and its reverse (789347347661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166743743987 - 2⁶ = 166743743923 is a prime.

It is not a weakly prime, because it can be changed into another prime (166743743927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83371871993 + 83371871994.

It is an arithmetic number, because the mean of its divisors is an integer number (83371871994).

Almost surely, 2^166743743987 is an apocalyptic number.

166743743987 is a deficient number, since it is larger than the sum of its proper divisors (1).

166743743987 is an equidigital number, since it uses as much as digits as its factorization.

166743743987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 128024064, while the sum is 65.

The spelling of 166743743987 in words is "one hundred sixty-six billion, seven hundred forty-three million, seven hundred forty-three thousand, nine hundred eighty-seven".