165943807 has 4 divisors (see below), whose sum is σ = 166091920. Its totient is φ = 165795696.

The previous prime is 165943763. The next prime is 165943823. The reversal of 165943807 is 708349561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 708349561 = 23 ⋅30797807.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165943807 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165943847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72363 + ... + 74620.

It is an arithmetic number, because the mean of its divisors is an integer number (41522980).

Almost surely, 2^165943807 is an apocalyptic number.

165943807 is a deficient number, since it is larger than the sum of its proper divisors (148113).

165943807 is a wasteful number, since it uses less digits than its factorization.

165943807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148112.

The product of its (nonzero) digits is 181440, while the sum is 43.

The square root of 165943807 is about 12881.9178308201. The cubic root of 165943807 is about 549.5244451306.

The spelling of 165943807 in words is "one hundred sixty-five million, nine hundred forty-three thousand, eight hundred seven".