165809387 has 12 divisors (see below), whose sum is σ = 171940320. Its totient is φ = 159814512.

The previous prime is 165809363. The next prime is 165809401. The reversal of 165809387 is 783908561.

It is a happy number.

165809387 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 165809387 - 2⁸ = 165809131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165809087) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 833114 + ... + 833312.

It is an arithmetic number, because the mean of its divisors is an integer number (14328360).

Almost surely, 2^165809387 is an apocalyptic number.

165809387 is a deficient number, since it is larger than the sum of its proper divisors (6130933).

165809387 is an frugal number, since it uses more digits than its factorization.

165809387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 530 (or 331 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 47.

The square root of 165809387 is about 12876.6993829941. The cubic root of 165809387 is about 549.3760273596.

The spelling of 165809387 in words is "one hundred sixty-five million, eight hundred nine thousand, three hundred eighty-seven".