166505663 has 2 divisors, whose sum is σ = 166505664. Its totient is φ = 166505662.

The previous prime is 166505639. The next prime is 166505723. The reversal of 166505663 is 366505661.

It is a weak prime.

It is an emirp because it is prime and its reverse (366505661) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166505663 is a prime.

It is a super-2 number, since 2×166505663² = 55448271622139138, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166505623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83252831 + 83252832.

It is an arithmetic number, because the mean of its divisors is an integer number (83252832).

Almost surely, 2^166505663 is an apocalyptic number.

166505663 is a deficient number, since it is larger than the sum of its proper divisors (1).

166505663 is an equidigital number, since it uses as much as digits as its factorization.

166505663 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 97200, while the sum is 38.

The square root of 166505663 is about 12903.7073354908. The cubic root of 166505663 is about 550.1439435916.

The spelling of 166505663 in words is "one hundred sixty-six million, five hundred five thousand, six hundred sixty-three".