71566454081 has 4 divisors (see below), whose sum is σ = 71863410564. Its totient is φ = 71269497600.

The previous prime is 71566454041. The next prime is 71566454119. The reversal of 71566454081 is 18045466517.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18045466517 = 13 ⋅1388112809.

It can be written as a sum of positive squares in 2 ways, for example, as 38805454081 + 32761000000 = 196991^2 + 181000^2 .

It is a cyclic number.

It is not a de Polignac number, because 71566454081 - 2¹⁴ = 71566437697 is a prime.

It is a super-2 number, since 2×71566454081² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71566454041) 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, 148477880 + ... + 148478361.

It is an arithmetic number, because the mean of its divisors is an integer number (17965852641).

Almost surely, 2^71566454081 is an apocalyptic number.

It is an amenable number.

71566454081 is a deficient number, since it is larger than the sum of its proper divisors (296956483).

71566454081 is a wasteful number, since it uses less digits than its factorization.

71566454081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296956482.

The product of its (nonzero) digits is 806400, while the sum is 47.

The spelling of 71566454081 in words is "seventy-one billion, five hundred sixty-six million, four hundred fifty-four thousand, eighty-one".