168987971 has 2 divisors, whose sum is σ = 168987972. Its totient is φ = 168987970.

The previous prime is 168987947. The next prime is 168988063. The reversal of 168987971 is 179789861.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 168987971 - 2¹⁸ = 168725827 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (168917971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84493985 + 84493986.

It is an arithmetic number, because the mean of its divisors is an integer number (84493986).

Almost surely, 2^168987971 is an apocalyptic number.

168987971 is a deficient number, since it is larger than the sum of its proper divisors (1).

168987971 is an equidigital number, since it uses as much as digits as its factorization.

168987971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1524096, while the sum is 56.

The square root of 168987971 is about 12999.5373379209. The cubic root of 168987971 is about 552.8643635749.

The spelling of 168987971 in words is "one hundred sixty-eight million, nine hundred eighty-seven thousand, nine hundred seventy-one".