161965903 has 8 divisors (see below), whose sum is σ = 179111376. Its totient is φ = 145224000.

The previous prime is 161965897. The next prime is 161965939. The reversal of 161965903 is 309569161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161965903 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 (161965963) 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 7 ways as a sum of consecutive naturals, for example, 100048 + ... + 101653.

It is an arithmetic number, because the mean of its divisors is an integer number (22388922).

Almost surely, 2^161965903 is an apocalyptic number.

161965903 is a deficient number, since it is larger than the sum of its proper divisors (17145473).

161965903 is a wasteful number, since it uses less digits than its factorization.

161965903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201785.

The product of its (nonzero) digits is 43740, while the sum is 40.

The square root of 161965903 is about 12726.5825342077. The cubic root of 161965903 is about 545.0979292643.

The spelling of 161965903 in words is "one hundred sixty-one million, nine hundred sixty-five thousand, nine hundred three".