165971646 has 32 divisors (see below), whose sum is σ = 390523680. Its totient is φ = 52069248.

The previous prime is 165971633. The next prime is 165971647. The reversal of 165971646 is 646179561.

165971646 is a `hidden beast` number, since 1 + 6 + 597 + 16 + 46 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165971647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 89481 + ... + 91316.

It is an arithmetic number, because the mean of its divisors is an integer number (12203865).

Almost surely, 2^165971646 is an apocalyptic number.

165971646 is an abundant number, since it is smaller than the sum of its proper divisors (224552034).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

165971646 is a wasteful number, since it uses less digits than its factorization.

165971646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180825 (or 180819 counting only the distinct ones).

The product of its digits is 272160, while the sum is 45.

The square root of 165971646 is about 12882.9983311339. The cubic root of 165971646 is about 549.5551731140. Note that the first 3 decimals are identical.

The spelling of 165971646 in words is "one hundred sixty-five million, nine hundred seventy-one thousand, six hundred forty-six".