165220605 has 24 divisors (see below), whose sum is σ = 312418080. Its totient is φ = 80106720.

The previous prime is 165220589. The next prime is 165220613. The reversal of 165220605 is 506022561.

165220605 is a `hidden beast` number, since 1 + 6 + 52 + 2 + 0 + 605 = 666.

It is not a de Polignac number, because 165220605 - 2⁴ = 165220589 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 166395 + ... + 167384.

It is an arithmetic number, because the mean of its divisors is an integer number (13017420).

Almost surely, 2^165220605 is an apocalyptic number.

165220605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

165220605 is a deficient number, since it is larger than the sum of its proper divisors (147197475).

165220605 is a wasteful number, since it uses less digits than its factorization.

165220605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333801 (or 333798 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 165220605 is about 12853.8167483437. The cubic root of 165220605 is about 548.7249859309.

The spelling of 165220605 in words is "one hundred sixty-five million, two hundred twenty thousand, six hundred five".