165855006009 has 243 divisors, whose sum is σ = 321444308367. Its totient is φ = 82102204800.

The previous prime is 165855006007. The next prime is 165855006043. The reversal of 165855006009 is 900600558561.

165855006009 = 1³ + 2³ + ... + 902³.

It is a happy number.

The square root of 165855006009 is 407253.

It is a perfect power (a square), and thus also a powerful number.

165855006009 is a `hidden beast` number, since 1 + 6 + 5 + 85 + 500 + 60 + 0 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 7991823609 + 157863182400 = 89397^2 + 397320^2 .

It is not a de Polignac number, because 165855006009 - 2¹ = 165855006007 is a prime.

It is a super-2 number, since 2×165855006009² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (165855006007) by changing a digit.

It is a polite number, since it can be written in 242 ways as a sum of consecutive naturals, for example, 3857093142 + ... + 3857093184.

Almost surely, 2^165855006009 is an apocalyptic number.

165855006009 is the 407253-rd square number.

165855006009 is the 203627-th centered octagonal number.

It is an amenable number.

165855006009 is a deficient number, since it is larger than the sum of its proper divisors (155589302358).

165855006009 is a wasteful number, since it uses less digits than its factorization.

165855006009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210 (or 105 counting only the distinct ones).

The product of its (nonzero) digits is 324000, while the sum is 45.

The spelling of 165855006009 in words is "one hundred sixty-five billion, eight hundred fifty-five million, six thousand, nine".