165544505445561 has 48 divisors (see below), whose sum is σ = 263830642371072. Its totient is φ = 91876123722240.

The previous prime is 165544505445533. The next prime is 165544505445617.

165544505445561 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 165544505445561 - 2⁶ = 165544505445497 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 165544505445495 and 165544505445504.

It is not an unprimeable number, because it can be changed into a prime (165544505425561) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 362287945 + ... + 362744598.

It is an arithmetic number, because the mean of its divisors is an integer number (5496471716064).

Almost surely, 2^{165544505445561} is an apocalyptic number.

165544505445561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

165544505445561 is a deficient number, since it is larger than the sum of its proper divisors (98286136925511).

165544505445561 is a wasteful number, since it uses less digits than its factorization.

165544505445561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 725032622 (or 725032611 counting only the distinct ones).

The product of its (nonzero) digits is 144000000, while the sum is 60.

The spelling of 165544505445561 in words is "one hundred sixty-five trillion, five hundred forty-four billion, five hundred five million, four hundred forty-five thousand, five hundred sixty-one".