161803841 has 4 divisors (see below), whose sum is σ = 171321732. Its totient is φ = 152285952.

The previous prime is 161803823. The next prime is 161803897. The reversal of 161803841 is 148308161.

It is a happy number.

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 101586241 + 60217600 = 10079^2 + 7760^2 .

It is a cyclic number.

It is not a de Polignac number, because 161803841 - 2⁶ = 161803777 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161803798 and 161803807.

It is not an unprimeable number, because it can be changed into a prime (161803241) 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 3 ways as a sum of consecutive naturals, for example, 4758920 + ... + 4758953.

It is an arithmetic number, because the mean of its divisors is an integer number (42830433).

Almost surely, 2^161803841 is an apocalyptic number.

It is an amenable number.

161803841 is a deficient number, since it is larger than the sum of its proper divisors (9517891).

161803841 is an equidigital number, since it uses as much as digits as its factorization.

161803841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9517890.

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

The square root of 161803841 is about 12720.2138739881. The cubic root of 161803841 is about 544.9160614773.

The spelling of 161803841 in words is "one hundred sixty-one million, eight hundred three thousand, eight hundred forty-one".