165407509 has 2 divisors, whose sum is σ = 165407510. Its totient is φ = 165407508.

The previous prime is 165407471. The next prime is 165407519. The reversal of 165407509 is 905704561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 109202500 + 56205009 = 10450^2 + 7497^2 .

It is an emirp because it is prime and its reverse (905704561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 165407509 - 2⁷ = 165407381 is a prime.

It is a Chen prime.

It is equal to p_9260398 and since 165407509 and 9260398 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165407519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82703754 + 82703755.

It is an arithmetic number, because the mean of its divisors is an integer number (82703755).

Almost surely, 2^165407509 is an apocalyptic number.

It is an amenable number.

165407509 is a deficient number, since it is larger than the sum of its proper divisors (1).

165407509 is an equidigital number, since it uses as much as digits as its factorization.

165407509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 37800, while the sum is 37.

The square root of 165407509 is about 12861.0850630886. The cubic root of 165407509 is about 548.9318210009.

The spelling of 165407509 in words is "one hundred sixty-five million, four hundred seven thousand, five hundred nine".