166640447 has 2 divisors, whose sum is σ = 166640448. Its totient is φ = 166640446.

The previous prime is 166640417. The next prime is 166640491. The reversal of 166640447 is 744046661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 166640447 - 2⁸ = 166640191 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 166640447.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166640417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83320223 + 83320224.

It is an arithmetic number, because the mean of its divisors is an integer number (83320224).

Almost surely, 2^166640447 is an apocalyptic number.

166640447 is a deficient number, since it is larger than the sum of its proper divisors (1).

166640447 is an equidigital number, since it uses as much as digits as its factorization.

166640447 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96768, while the sum is 38.

The square root of 166640447 is about 12908.9289640930. The cubic root of 166640447 is about 550.2923481584.

The spelling of 166640447 in words is "one hundred sixty-six million, six hundred forty thousand, four hundred forty-seven".