165985025 has 12 divisors (see below), whose sum is σ = 217929132. Its totient is φ = 124976640.

The previous prime is 165985003. The next prime is 165985051. The reversal of 165985025 is 520589561.

It can be written as a sum of positive squares in 6 ways, for example, as 1324801 + 164660224 = 1151^2 + 12832^2 .

It is not a de Polignac number, because 165985025 - 2⁶ = 165984961 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 194852 + ... + 195701.

It is an arithmetic number, because the mean of its divisors is an integer number (18160761).

Almost surely, 2^165985025 is an apocalyptic number.

It is an amenable number.

165985025 is a deficient number, since it is larger than the sum of its proper divisors (51944107).

165985025 is a wasteful number, since it uses less digits than its factorization.

165985025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390580 (or 390575 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 41.

The square root of 165985025 is about 12883.5175709121. The cubic root of 165985025 is about 549.5699392930.

The spelling of 165985025 in words is "one hundred sixty-five million, nine hundred eighty-five thousand, twenty-five".