161865593 has 2 divisors, whose sum is σ = 161865594. Its totient is φ = 161865592.

The previous prime is 161865553. The next prime is 161865611. The reversal of 161865593 is 395568161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 95491984 + 66373609 = 9772^2 + 8147^2 .

It is a cyclic number.

It is not a de Polignac number, because 161865593 - 2⁸ = 161865337 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (161865523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80932796 + 80932797.

It is an arithmetic number, because the mean of its divisors is an integer number (80932797).

Almost surely, 2^161865593 is an apocalyptic number.

It is an amenable number.

161865593 is a deficient number, since it is larger than the sum of its proper divisors (1).

161865593 is an equidigital number, since it uses as much as digits as its factorization.

161865593 is an evil number, because the sum of its binary digits is even.

The product of its digits is 194400, while the sum is 44.

The square root of 161865593 is about 12722.6409601152. The cubic root of 161865593 is about 544.9853745760.

The spelling of 161865593 in words is "one hundred sixty-one million, eight hundred sixty-five thousand, five hundred ninety-three".