71000081 has 2 divisors, whose sum is σ = 71000082. Its totient is φ = 71000080.

The previous prime is 71000051. The next prime is 71000087. The reversal of 71000081 is 18000017.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41667025 + 29333056 = 6455^2 + 5416^2 .

It is a cyclic number.

It is not a de Polignac number, because 71000081 - 2¹⁴ = 70983697 is a prime.

It is a super-2 number, since 2×71000081² = 10082023004013122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (71000087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35500040 + 35500041.

It is an arithmetic number, because the mean of its divisors is an integer number (35500041).

Almost surely, 2^71000081 is an apocalyptic number.

It is an amenable number.

71000081 is a deficient number, since it is larger than the sum of its proper divisors (1).

71000081 is an equidigital number, since it uses as much as digits as its factorization.

71000081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56, while the sum is 17.

The square root of 71000081 is about 8426.1545796407. The cubic root of 71000081 is about 414.0819324099.

Adding to 71000081 its reverse (18000017), we get a palindrome (89000098).

The spelling of 71000081 in words is "seventy-one million, eighty-one", and thus it is an aban number and an uban number.