165265562561 has 4 divisors (see below), whose sum is σ = 180289704624. Its totient is φ = 150241420500.

The previous prime is 165265562513. The next prime is 165265562563.

165265562561 is nontrivially palindromic in base 10.

165265562561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 165265562561 - 2¹⁰ = 165265561537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (165265562563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7512071015 + ... + 7512071036.

It is an arithmetic number, because the mean of its divisors is an integer number (45072426156).

Almost surely, 2^165265562561 is an apocalyptic number.

165265562561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

165265562561 is a deficient number, since it is larger than the sum of its proper divisors (15024142063).

165265562561 is a wasteful number, since it uses less digits than its factorization.

165265562561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15024142062.

The product of its digits is 3240000, while the sum is 50.

The spelling of 165265562561 in words is "one hundred sixty-five billion, two hundred sixty-five million, five hundred sixty-two thousand, five hundred sixty-one".