165878149 has 2 divisors, whose sum is σ = 165878150. Its totient is φ = 165878148.

The previous prime is 165878147. The next prime is 165878159. The reversal of 165878149 is 941878561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 138650625 + 27227524 = 11775^2 + 5218^2 .

It is a cyclic number.

It is not a de Polignac number, because 165878149 - 2¹ = 165878147 is a prime.

Together with 165878147, it forms a pair of twin primes.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165878147) 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, 82939074 + 82939075.

It is an arithmetic number, because the mean of its divisors is an integer number (82939075).

Almost surely, 2^165878149 is an apocalyptic number.

It is an amenable number.

165878149 is a deficient number, since it is larger than the sum of its proper divisors (1).

165878149 is an equidigital number, since it uses as much as digits as its factorization.

165878149 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 483840, while the sum is 49.

The square root of 165878149 is about 12879.3691227482. The cubic root of 165878149 is about 549.4519598793.

The spelling of 165878149 in words is "one hundred sixty-five million, eight hundred seventy-eight thousand, one hundred forty-nine".