166557042593 has 2 divisors, whose sum is σ = 166557042594. Its totient is φ = 166557042592.

The previous prime is 166557042563. The next prime is 166557042611. The reversal of 166557042593 is 395240755661.

166557042593 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 97034119009 + 69522923584 = 311503^2 + 263672^2 .

It is a cyclic number.

It is not a de Polignac number, because 166557042593 - 2¹⁶ = 166556977057 is a prime.

It is not a weakly prime, because it can be changed into another prime (166557042523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83278521296 + 83278521297.

It is an arithmetic number, because the mean of its divisors is an integer number (83278521297).

Almost surely, 2^166557042593 is an apocalyptic number.

It is an amenable number.

166557042593 is a deficient number, since it is larger than the sum of its proper divisors (1).

166557042593 is an equidigital number, since it uses as much as digits as its factorization.

166557042593 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6804000, while the sum is 53.

The spelling of 166557042593 in words is "one hundred sixty-six billion, five hundred fifty-seven million, forty-two thousand, five hundred ninety-three".