165541543613 has 2 divisors, whose sum is σ = 165541543614. Its totient is φ = 165541543612.

The previous prime is 165541543597. The next prime is 165541543619. The reversal of 165541543613 is 316345145561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 156520723129 + 9020820484 = 395627^2 + 94978^2 .

It is an emirp because it is prime and its reverse (316345145561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 165541543613 - 2⁴ = 165541543597 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165541543619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82770771806 + 82770771807.

It is an arithmetic number, because the mean of its divisors is an integer number (82770771807).

Almost surely, 2^165541543613 is an apocalyptic number.

It is an amenable number.

165541543613 is a deficient number, since it is larger than the sum of its proper divisors (1).

165541543613 is an equidigital number, since it uses as much as digits as its factorization.

165541543613 is an evil number, because the sum of its binary digits is even.

The product of its digits is 648000, while the sum is 44.

The spelling of 165541543613 in words is "one hundred sixty-five billion, five hundred forty-one million, five hundred forty-three thousand, six hundred thirteen".