165239989 has 2 divisors, whose sum is σ = 165239990. Its totient is φ = 165239988.

The previous prime is 165239929. The next prime is 165240029. The reversal of 165239989 is 989932561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 135722500 + 29517489 = 11650^2 + 5433^2 .

It is a cyclic number.

It is not a de Polignac number, because 165239989 - 2¹⁵ = 165207221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165239909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82619994 + 82619995.

It is an arithmetic number, because the mean of its divisors is an integer number (82619995).

Almost surely, 2^165239989 is an apocalyptic number.

It is an amenable number.

165239989 is a deficient number, since it is larger than the sum of its proper divisors (1).

165239989 is an equidigital number, since it uses as much as digits as its factorization.

165239989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1049760, while the sum is 52.

The square root of 165239989 is about 12854.5707435138. The cubic root of 165239989 is about 548.7464442496.

The spelling of 165239989 in words is "one hundred sixty-five million, two hundred thirty-nine thousand, nine hundred eighty-nine".