165605123 has 2 divisors, whose sum is σ = 165605124. Its totient is φ = 165605122.

The previous prime is 165605101. The next prime is 165605147. The reversal of 165605123 is 321506561.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 165605123 - 2⁸ = 165604867 is a prime.

It is not a weakly prime, because it can be changed into another prime (165601123) 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, 82802561 + 82802562.

It is an arithmetic number, because the mean of its divisors is an integer number (82802562).

Almost surely, 2^165605123 is an apocalyptic number.

165605123 is a deficient number, since it is larger than the sum of its proper divisors (1).

165605123 is an equidigital number, since it uses as much as digits as its factorization.

165605123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 165605123 is about 12868.7654030991. The cubic root of 165605123 is about 549.1503387752.

The spelling of 165605123 in words is "one hundred sixty-five million, six hundred five thousand, one hundred twenty-three".