165664042 has 4 divisors (see below), whose sum is σ = 248496066. Its totient is φ = 82832020.

The previous prime is 165664039. The next prime is 165664043. The reversal of 165664042 is 240466561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 240466561 = 907 ⋅265123.

It can be written as a sum of positive squares in only one way, i.e., 162282121 + 3381921 = 12739^2 + 1839^2 .

It is a junction number, because it is equal to n+sod(n) for n = 165663989 and 165664007.

It is not an unprimeable number, because it can be changed into a prime (165664043) 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, 41416009 + ... + 41416012.

Almost surely, 2^165664042 is an apocalyptic number.

165664042 is a deficient number, since it is larger than the sum of its proper divisors (82832024).

165664042 is an equidigital number, since it uses as much as digits as its factorization.

165664042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82832023.

The product of its (nonzero) digits is 34560, while the sum is 34.

The square root of 165664042 is about 12871.0544245606. The cubic root of 165664042 is about 549.2154566327.

The spelling of 165664042 in words is "one hundred sixty-five million, six hundred sixty-four thousand, forty-two".