165557983 has 4 divisors (see below), whose sum is σ = 165940768. Its totient is φ = 165175200.

The previous prime is 165557981. The next prime is 165557999. The reversal of 165557983 is 389755561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 165557983 - 2¹ = 165557981 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 (165557981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 190743 + ... + 191608.

It is an arithmetic number, because the mean of its divisors is an integer number (41485192).

Almost surely, 2^165557983 is an apocalyptic number.

165557983 is a deficient number, since it is larger than the sum of its proper divisors (382785).

165557983 is an equidigital number, since it uses as much as digits as its factorization.

165557983 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 382784.

The product of its digits is 1134000, while the sum is 49.

The square root of 165557983 is about 12866.9337062099. The cubic root of 165557983 is about 549.0982280611.

The spelling of 165557983 in words is "one hundred sixty-five million, five hundred fifty-seven thousand, nine hundred eighty-three".