161785065 has 32 divisors (see below), whose sum is σ = 280062720. Its totient is φ = 79278336.

The previous prime is 161785061. The next prime is 161785069. The reversal of 161785065 is 560587161.

It is an interprime number because it is at equal distance from previous prime (161785061) and next prime (161785069).

It is not a de Polignac number, because 161785065 - 2² = 161785061 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (161785061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 42844 + ... + 46466.

It is an arithmetic number, because the mean of its divisors is an integer number (8751960).

Almost surely, 2^161785065 is an apocalyptic number.

161785065 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161785065 is a deficient number, since it is larger than the sum of its proper divisors (118277655).

161785065 is a wasteful number, since it uses less digits than its factorization.

161785065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3873.

The product of its (nonzero) digits is 50400, while the sum is 39.

The square root of 161785065 is about 12719.4758146710. The cubic root of 161785065 is about 544.8949829918.

The spelling of 161785065 in words is "one hundred sixty-one million, seven hundred eighty-five thousand, sixty-five".