165445666403 has 4 divisors (see below), whose sum is σ = 165451255680. Its totient is φ = 165440077128.

The previous prime is 165445666387. The next prime is 165445666423. The reversal of 165445666403 is 304666544561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 165445666403 - 2⁴ = 165445666387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165445666423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2750000 + ... + 2809517.

It is an arithmetic number, because the mean of its divisors is an integer number (41362813920).

Almost surely, 2^165445666403 is an apocalyptic number.

165445666403 is a deficient number, since it is larger than the sum of its proper divisors (5589277).

165445666403 is an equidigital number, since it uses as much as digits as its factorization.

165445666403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5589276.

The product of its (nonzero) digits is 6220800, while the sum is 50.

The spelling of 165445666403 in words is "one hundred sixty-five billion, four hundred forty-five million, six hundred sixty-six thousand, four hundred three".