165441158255521 has 4 divisors (see below), whose sum is σ = 167707475491972. Its totient is φ = 163174841019072.

The previous prime is 165441158255497. The next prime is 165441158255543. The reversal of 165441158255521 is 125552851144561.

165441158255521 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.

It can be written as a sum of positive squares in 2 ways, for example, as 117322172119296 + 48118986136225 = 10831536^2 + 6936785^2 .

It is a cyclic number.

It is not a de Polignac number, because 165441158255521 - 2¹¹ = 165441158253473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165441158253521) 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, 1133158618116 + ... + 1133158618261.

It is an arithmetic number, because the mean of its divisors is an integer number (41926868872993).

Almost surely, 2^{165441158255521} is an apocalyptic number.

It is an amenable number.

165441158255521 is a deficient number, since it is larger than the sum of its proper divisors (2266317236451).

165441158255521 is an equidigital number, since it uses as much as digits as its factorization.

165441158255521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2266317236450.

The product of its digits is 9600000, while the sum is 55.

The spelling of 165441158255521 in words is "one hundred sixty-five trillion, four hundred forty-one billion, one hundred fifty-eight million, two hundred fifty-five thousand, five hundred twenty-one".