164785909 has 4 divisors (see below), whose sum is σ = 165639916. Its totient is φ = 163931904.

The previous prime is 164785891. The next prime is 164785921. The reversal of 164785909 is 909587461.

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

It can be written as a sum of positive squares in 2 ways, for example, as 62331025 + 102454884 = 7895^2 + 10122^2 .

It is a cyclic number.

It is not a de Polignac number, because 164785909 - 2⁵ = 164785877 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 (164785609) 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, 426714 + ... + 427099.

It is an arithmetic number, because the mean of its divisors is an integer number (41409979).

Almost surely, 2^164785909 is an apocalyptic number.

It is an amenable number.

164785909 is a deficient number, since it is larger than the sum of its proper divisors (854007).

164785909 is an equidigital number, since it uses as much as digits as its factorization.

164785909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 854006.

The product of its (nonzero) digits is 544320, while the sum is 49.

The square root of 164785909 is about 12836.8963928202. The cubic root of 164785909 is about 548.2433308076.

The spelling of 164785909 in words is "one hundred sixty-four million, seven hundred eighty-five thousand, nine hundred nine".