165606503 has 16 divisors (see below), whose sum is σ = 183054816. Its totient is φ = 149160960.

The previous prime is 165606491. The next prime is 165606523. The reversal of 165606503 is 305606561.

It is a cyclic number.

It is not a de Polignac number, because 165606503 - 2²⁰ = 164557927 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 165606503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165606523) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34700 + ... + 39182.

It is an arithmetic number, because the mean of its divisors is an integer number (11440926).

Almost surely, 2^165606503 is an apocalyptic number.

165606503 is a deficient number, since it is larger than the sum of its proper divisors (17448313).

165606503 is a wasteful number, since it uses less digits than its factorization.

165606503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4594.

The product of its (nonzero) digits is 16200, while the sum is 32.

The square root of 165606503 is about 12868.8190211845. The cubic root of 165606503 is about 549.1518641414.

The spelling of 165606503 in words is "one hundred sixty-five million, six hundred six thousand, five hundred three".