165551171155537 has 2 divisors, whose sum is σ = 165551171155538. Its totient is φ = 165551171155536.

The previous prime is 165551171155529. The next prime is 165551171155589. The reversal of 165551171155537 is 735551171155561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 149595428508241 + 15955742647296 = 12230921^2 + 3994464^2 .

It is a cyclic number.

It is not a de Polignac number, because 165551171155537 - 2³ = 165551171155529 is a prime.

It is not a weakly prime, because it can be changed into another prime (165551171155597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82775585577768 + 82775585577769.

It is an arithmetic number, because the mean of its divisors is an integer number (82775585577769).

Almost surely, 2^{165551171155537} is an apocalyptic number.

It is an amenable number.

165551171155537 is a deficient number, since it is larger than the sum of its proper divisors (1).

165551171155537 is an equidigital number, since it uses as much as digits as its factorization.

165551171155537 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13781250, while the sum is 58.

The spelling of 165551171155537 in words is "one hundred sixty-five trillion, five hundred fifty-one billion, one hundred seventy-one million, one hundred fifty-five thousand, five hundred thirty-seven".