81040415017 has 4 divisors (see below), whose sum is σ = 81043962580. Its totient is φ = 81036867456.

The previous prime is 81040414999. The next prime is 81040415023. The reversal of 81040415017 is 71051404018.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 38810576016 + 42229839001 = 197004^2 + 205499^2 .

It is a cyclic number.

It is not a de Polignac number, because 81040415017 - 2¹¹ = 81040412969 is a prime.

It is a super-2 number, since 2×81040415017² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81040415017.

It is not an unprimeable number, because it can be changed into a prime (81040415717) 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, 1739292 + ... + 1785277.

It is an arithmetic number, because the mean of its divisors is an integer number (20260990645).

Almost surely, 2^81040415017 is an apocalyptic number.

It is an amenable number.

81040415017 is a deficient number, since it is larger than the sum of its proper divisors (3547563).

81040415017 is a wasteful number, since it uses less digits than its factorization.

81040415017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3547562.

The product of its (nonzero) digits is 4480, while the sum is 31.

The spelling of 81040415017 in words is "eighty-one billion, forty million, four hundred fifteen thousand, seventeen".