161847181 has 2 divisors, whose sum is σ = 161847182. Its totient is φ = 161847180.

The previous prime is 161847151. The next prime is 161847193. The reversal of 161847181 is 181748161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 129185956 + 32661225 = 11366^2 + 5715^2 .

It is a cyclic number.

It is not a de Polignac number, because 161847181 - 2²⁷ = 27629453 is a prime.

It is a super-2 number, since 2×161847181² = 52389019995293522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 161847181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161847151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80923590 + 80923591.

It is an arithmetic number, because the mean of its divisors is an integer number (80923591).

Almost surely, 2^161847181 is an apocalyptic number.

It is an amenable number.

161847181 is a deficient number, since it is larger than the sum of its proper divisors (1).

161847181 is an equidigital number, since it uses as much as digits as its factorization.

161847181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10752, while the sum is 37.

The square root of 161847181 is about 12721.9173476328. The cubic root of 161847181 is about 544.9647100007.

The spelling of 161847181 in words is "one hundred sixty-one million, eight hundred forty-seven thousand, one hundred eighty-one".