166640465 has 4 divisors (see below), whose sum is σ = 199968564. Its totient is φ = 133312368.

The previous prime is 166640447. The next prime is 166640491. The reversal of 166640465 is 564046661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 124701889 + 41938576 = 11167^2 + 6476^2 .

It is a cyclic number.

It is not a de Polignac number, because 166640465 - 2¹⁰ = 166639441 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 16664042 + ... + 16664051.

It is an arithmetic number, because the mean of its divisors is an integer number (49992141).

Almost surely, 2^166640465 is an apocalyptic number.

It is an amenable number.

166640465 is a deficient number, since it is larger than the sum of its proper divisors (33328099).

166640465 is an equidigital number, since it uses as much as digits as its factorization.

166640465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33328098.

The product of its (nonzero) digits is 103680, while the sum is 38.

The square root of 166640465 is about 12908.9296612849. The cubic root of 166640465 is about 550.2923679720.

The spelling of 166640465 in words is "one hundred sixty-six million, six hundred forty thousand, four hundred sixty-five".