161816441 has 4 divisors (see below), whose sum is σ = 165259392. Its totient is φ = 158373492.

The previous prime is 161816423. The next prime is 161816449. The reversal of 161816441 is 144618161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 161816441 - 2⁶ = 161816377 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161816398 and 161816407.

It is not an unprimeable number, because it can be changed into a prime (161816449) 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, 1721405 + ... + 1721498.

It is an arithmetic number, because the mean of its divisors is an integer number (41314848).

Almost surely, 2^161816441 is an apocalyptic number.

It is an amenable number.

161816441 is a deficient number, since it is larger than the sum of its proper divisors (3442951).

161816441 is an equidigital number, since it uses as much as digits as its factorization.

161816441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3442950.

The product of its digits is 4608, while the sum is 32.

The square root of 161816441 is about 12720.7091390378. The cubic root of 161816441 is about 544.9302056907.

It can be divided in two parts, 16181 and 6441, that added together give a palindrome (22622).

The spelling of 161816441 in words is "one hundred sixty-one million, eight hundred sixteen thousand, four hundred forty-one".