165510557 has 2 divisors, whose sum is σ = 165510558. Its totient is φ = 165510556.

The previous prime is 165510551. The next prime is 165510617. The reversal of 165510557 is 755015561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 144817156 + 20693401 = 12034^2 + 4549^2 .

It is a cyclic number.

It is not a de Polignac number, because 165510557 - 2⁶ = 165510493 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165510551) 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 as a sum of consecutive naturals, namely, 82755278 + 82755279.

It is an arithmetic number, because the mean of its divisors is an integer number (82755279).

Almost surely, 2^165510557 is an apocalyptic number.

It is an amenable number.

165510557 is a deficient number, since it is larger than the sum of its proper divisors (1).

165510557 is an equidigital number, since it uses as much as digits as its factorization.

165510557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26250, while the sum is 35.

The square root of 165510557 is about 12865.0906331825. The cubic root of 165510557 is about 549.0457912066.

The spelling of 165510557 in words is "one hundred sixty-five million, five hundred ten thousand, five hundred fifty-seven".