165546881 has 2 divisors, whose sum is σ = 165546882. Its totient is φ = 165546880.

The previous prime is 165546859. The next prime is 165546907. The reversal of 165546881 is 188645561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 165379600 + 167281 = 12860^2 + 409^2 .

It is a cyclic number.

It is not a de Polignac number, because 165546881 - 2⁶ = 165546817 is a prime.

It is a super-2 number, since 2×165546881² = 54811539617656322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (165546811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82773440 + 82773441.

It is an arithmetic number, because the mean of its divisors is an integer number (82773441).

Almost surely, 2^165546881 is an apocalyptic number.

It is an amenable number.

165546881 is a deficient number, since it is larger than the sum of its proper divisors (1).

165546881 is an equidigital number, since it uses as much as digits as its factorization.

165546881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 230400, while the sum is 44.

The square root of 165546881 is about 12866.5022830605. The cubic root of 165546881 is about 549.0859539630.

The spelling of 165546881 in words is "one hundred sixty-five million, five hundred forty-six thousand, eight hundred eighty-one".