71643161 has 2 divisors, whose sum is σ = 71643162. Its totient is φ = 71643160.

The previous prime is 71643157. The next prime is 71643163. The reversal of 71643161 is 16134617.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49843600 + 21799561 = 7060^2 + 4669^2 .

It is an emirp because it is prime and its reverse (16134617) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71643161 - 2² = 71643157 is a prime.

It is a Sophie Germain prime.

Together with 71643163, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (71643163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35821580 + 35821581.

It is an arithmetic number, because the mean of its divisors is an integer number (35821581).

Almost surely, 2^71643161 is an apocalyptic number.

It is an amenable number.

71643161 is a deficient number, since it is larger than the sum of its proper divisors (1).

71643161 is an equidigital number, since it uses as much as digits as its factorization.

71643161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3024, while the sum is 29.

The square root of 71643161 is about 8464.2283168639. The cubic root of 71643161 is about 415.3283528991.

Adding to 71643161 its reverse (16134617), we get a palindrome (87777778).

The spelling of 71643161 in words is "seventy-one million, six hundred forty-three thousand, one hundred sixty-one".