161847817 has 2 divisors, whose sum is σ = 161847818. Its totient is φ = 161847816.

The previous prime is 161847809. The next prime is 161847841. The reversal of 161847817 is 718748161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 141633801 + 20214016 = 11901^2 + 4496^2 .

It is a cyclic number.

It is not a de Polignac number, because 161847817 - 2³ = 161847809 is a prime.

It is not a weakly prime, because it can be changed into another prime (161847617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80923908 + 80923909.

It is an arithmetic number, because the mean of its divisors is an integer number (80923909).

Almost surely, 2^161847817 is an apocalyptic number.

It is an amenable number.

161847817 is a deficient number, since it is larger than the sum of its proper divisors (1).

161847817 is an equidigital number, since it uses as much as digits as its factorization.

161847817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 75264, while the sum is 43.

The square root of 161847817 is about 12721.9423438404. The cubic root of 161847817 is about 544.9654238368.

The spelling of 161847817 in words is "one hundred sixty-one million, eight hundred forty-seven thousand, eight hundred seventeen".