165642089 has 2 divisors, whose sum is σ = 165642090. Its totient is φ = 165642088.

The previous prime is 165642079. The next prime is 165642109. The reversal of 165642089 is 980246561.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 106090000 + 59552089 = 10300^2 + 7717^2 .

It is a cyclic number.

It is not a de Polignac number, because 165642089 - 2¹² = 165637993 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (165642049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82821044 + 82821045.

It is an arithmetic number, because the mean of its divisors is an integer number (82821045).

Almost surely, 2^165642089 is an apocalyptic number.

It is an amenable number.

165642089 is a deficient number, since it is larger than the sum of its proper divisors (1).

165642089 is an equidigital number, since it uses as much as digits as its factorization.

165642089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 41.

The square root of 165642089 is about 12870.2015912728. The cubic root of 165642089 is about 549.1911957664.

The spelling of 165642089 in words is "one hundred sixty-five million, six hundred forty-two thousand, eighty-nine".