165989387 has 2 divisors, whose sum is σ = 165989388. Its totient is φ = 165989386.

The previous prime is 165989353. The next prime is 165989423. The reversal of 165989387 is 783989561.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 165989387 - 2¹⁰ = 165988363 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (165989347) 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, 82994693 + 82994694.

It is an arithmetic number, because the mean of its divisors is an integer number (82994694).

Almost surely, 2^165989387 is an apocalyptic number.

165989387 is a deficient number, since it is larger than the sum of its proper divisors (1).

165989387 is an equidigital number, since it uses as much as digits as its factorization.

165989387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3265920, while the sum is 56.

The square root of 165989387 is about 12883.6868558654. The cubic root of 165989387 is about 549.5747533881.

The spelling of 165989387 in words is "one hundred sixty-five million, nine hundred eighty-nine thousand, three hundred eighty-seven".