166456993 has 2 divisors, whose sum is σ = 166456994. Its totient is φ = 166456992.

The previous prime is 166456991. The next prime is 166457041. The reversal of 166456993 is 399654661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 133818624 + 32638369 = 11568^2 + 5713^2 .

It is a cyclic number.

It is not a de Polignac number, because 166456993 - 2¹ = 166456991 is a prime.

Together with 166456991, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (166456991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83228496 + 83228497.

It is an arithmetic number, because the mean of its divisors is an integer number (83228497).

Almost surely, 2^166456993 is an apocalyptic number.

It is an amenable number.

166456993 is a deficient number, since it is larger than the sum of its proper divisors (1).

166456993 is an equidigital number, since it uses as much as digits as its factorization.

166456993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1049760, while the sum is 49.

The square root of 166456993 is about 12901.8213055367. The cubic root of 166456993 is about 550.0903355751.

The spelling of 166456993 in words is "one hundred sixty-six million, four hundred fifty-six thousand, nine hundred ninety-three".