166400123 has 2 divisors, whose sum is σ = 166400124. Its totient is φ = 166400122.

The previous prime is 166400093. The next prime is 166400141. The reversal of 166400123 is 321004661.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 166400123 - 2⁸ = 166399867 is a prime.

It is not a weakly prime, because it can be changed into another prime (166400183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83200061 + 83200062.

It is an arithmetic number, because the mean of its divisors is an integer number (83200062).

Almost surely, 2^166400123 is an apocalyptic number.

166400123 is a deficient number, since it is larger than the sum of its proper divisors (1).

166400123 is an equidigital number, since it uses as much as digits as its factorization.

166400123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 166400123 is about 12899.6171648619. The cubic root of 166400123 is about 550.0276823532.

Adding to 166400123 its reverse (321004661), we get a palindrome (487404784).

The spelling of 166400123 in words is "one hundred sixty-six million, four hundred thousand, one hundred twenty-three".