165131421365 has 4 divisors (see below), whose sum is σ = 198157705644. Its totient is φ = 132105137088.

The previous prime is 165131421317. The next prime is 165131421373. The reversal of 165131421365 is 563124131561.

165131421365 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 an emirpimes, since its reverse is a distinct semiprime: 563124131561 = 9043 ⋅62271827.

It can be written as a sum of positive squares in 2 ways, for example, as 86286712516 + 78844708849 = 293746^2 + 280793^2 .

It is a cyclic number.

It is not a de Polignac number, because 165131421365 - 2¹⁴ = 165131404981 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 16513142132 + ... + 16513142141.

It is an arithmetic number, because the mean of its divisors is an integer number (49539426411).

Almost surely, 2^165131421365 is an apocalyptic number.

It is an amenable number.

165131421365 is a deficient number, since it is larger than the sum of its proper divisors (33026284279).

165131421365 is an equidigital number, since it uses as much as digits as its factorization.

165131421365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33026284278.

The product of its digits is 64800, while the sum is 38.

The spelling of 165131421365 in words is "one hundred sixty-five billion, one hundred thirty-one million, four hundred twenty-one thousand, three hundred sixty-five".