161813983 has 4 divisors (see below), whose sum is σ = 161852040. Its totient is φ = 161775928.

The previous prime is 161813963. The next prime is 161814011. The reversal of 161813983 is 389318161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 389318161 = 317 ⋅1228133.

It is a cyclic number.

It is not a de Polignac number, because 161813983 - 2⁹ = 161813471 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 (161813923) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11713 + ... + 21466.

It is an arithmetic number, because the mean of its divisors is an integer number (40463010).

Almost surely, 2^161813983 is an apocalyptic number.

161813983 is a deficient number, since it is larger than the sum of its proper divisors (38057).

161813983 is an equidigital number, since it uses as much as digits as its factorization.

161813983 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38056.

The product of its digits is 31104, while the sum is 40.

The square root of 161813983 is about 12720.6125245603. The cubic root of 161813983 is about 544.9274465042.

It can be divided in two parts, 16181 and 3983, that added together give a square (20164 = 142²).

The spelling of 161813983 in words is "one hundred sixty-one million, eight hundred thirteen thousand, nine hundred eighty-three".