71318081 has 4 divisors (see below), whose sum is σ = 71572164. Its totient is φ = 71064000.

The previous prime is 71318059. The next prime is 71318099. The reversal of 71318081 is 18081317.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18081317 = 59 ⋅306463.

It can be written as a sum of positive squares in 2 ways, for example, as 46117681 + 25200400 = 6791^2 + 5020^2 .

It is a cyclic number.

It is not a de Polignac number, because 71318081 - 2⁶ = 71318017 is a prime.

It is a super-2 number, since 2×71318081² = 10172537355045122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (71318981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126620 + ... + 127181.

It is an arithmetic number, because the mean of its divisors is an integer number (17893041).

Almost surely, 2^71318081 is an apocalyptic number.

It is an amenable number.

71318081 is a deficient number, since it is larger than the sum of its proper divisors (254083).

71318081 is a wasteful number, since it uses less digits than its factorization.

71318081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 254082.

The product of its (nonzero) digits is 1344, while the sum is 29.

The square root of 71318081 is about 8445.0033155707. The cubic root of 71318081 is about 414.6992178685.

Adding to 71318081 its reverse (18081317), we get a palindrome (89399398).

The spelling of 71318081 in words is "seventy-one million, three hundred eighteen thousand, eighty-one".