161391841 has 4 divisors (see below), whose sum is σ = 173806612. Its totient is φ = 148977072.

The previous prime is 161391827. The next prime is 161391847. The reversal of 161391841 is 148193161.

161391841 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 24010000 + 137381841 = 4900^2 + 11721^2 .

It is a cyclic number.

It is not a de Polignac number, because 161391841 - 2¹⁷ = 161260769 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161391797 and 161391806.

It is not an unprimeable number, because it can be changed into a prime (161391847) 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, 6207366 + ... + 6207391.

It is an arithmetic number, because the mean of its divisors is an integer number (43451653).

Almost surely, 2^161391841 is an apocalyptic number.

It is an amenable number.

161391841 is a deficient number, since it is larger than the sum of its proper divisors (12414771).

161391841 is a wasteful number, since it uses less digits than its factorization.

161391841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12414770.

The product of its digits is 5184, while the sum is 34.

The square root of 161391841 is about 12704.0088554755. The cubic root of 161391841 is about 544.4531630316.

The spelling of 161391841 in words is "one hundred sixty-one million, three hundred ninety-one thousand, eight hundred forty-one".