165162545261561 has 4 divisors (see below), whose sum is σ = 165204710837412. Its totient is φ = 165120379685712.

The previous prime is 165162545261551. The next prime is 165162545261617.

165162545261561 is nontrivially palindromic in base 10.

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

It can be written as a sum of positive squares in 2 ways, for example, as 155506361907961 + 9656183353600 = 12470219^2 + 3107440^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165162545261561 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 165162545261497 and 165162545261506.

It is not an unprimeable number, because it can be changed into a prime (165162545261531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21082782050 + ... + 21082789883.

It is an arithmetic number, because the mean of its divisors is an integer number (41301177709353).

Almost surely, 2^{165162545261561} is an apocalyptic number.

It is an amenable number.

165162545261561 is a deficient number, since it is larger than the sum of its proper divisors (42165575851).

165162545261561 is an equidigital number, since it uses as much as digits as its factorization.

165162545261561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42165575850.

The product of its digits is 12960000, while the sum is 56.

The spelling of 165162545261561 in words is "one hundred sixty-five trillion, one hundred sixty-two billion, five hundred forty-five million, two hundred sixty-one thousand, five hundred sixty-one".