201605985 has 24 divisors (see below), whose sum is σ = 399372480. Its totient is φ = 92162592.

The previous prime is 201605969. The next prime is 201605993. The reversal of 201605985 is 589506102.

It is a happy number.

201605985 is a `hidden beast` number, since 2 + 0 + 1 + 60 + 598 + 5 = 666.

It is not a de Polignac number, because 201605985 - 2⁴ = 201605969 is a prime.

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, 319695 + ... + 320324.

It is an arithmetic number, because the mean of its divisors is an integer number (16640520).

Almost surely, 2^201605985 is an apocalyptic number.

It is an amenable number.

201605985 is a deficient number, since it is larger than the sum of its proper divisors (197766495).

201605985 is a wasteful number, since it uses less digits than its factorization.

201605985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640037 (or 640034 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 201605985 is about 14198.8022382171. The cubic root of 201605985 is about 586.3646860037.

The spelling of 201605985 in words is "two hundred one million, six hundred five thousand, nine hundred eighty-five".