81061016017 has 4 divisors (see below), whose sum is σ = 81863600436. Its totient is φ = 80258431600.

The previous prime is 81061015999. The next prime is 81061016051. The reversal of 81061016017 is 71061016018.

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 63025600401 + 18035415616 = 251049^2 + 134296^2 .

It is a cyclic number.

It is not a de Polignac number, because 81061016017 - 2¹⁵ = 81060983249 is a prime.

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 81061016017.

It is not an unprimeable number, because it can be changed into a prime (81061016117) 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, 401292058 + ... + 401292259.

It is an arithmetic number, because the mean of its divisors is an integer number (20465900109).

Almost surely, 2^81061016017 is an apocalyptic number.

It is an amenable number.

81061016017 is a deficient number, since it is larger than the sum of its proper divisors (802584419).

81061016017 is a wasteful number, since it uses less digits than its factorization.

81061016017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 802584418.

The product of its (nonzero) digits is 2016, while the sum is 31.

Subtracting from 81061016017 its reverse (71061016018), we obtain a palindrome (9999999999).

It can be divided in two parts, 8106101 and 6017, that added together give a palindrome (8112118).

The spelling of 81061016017 in words is "eighty-one billion, sixty-one million, sixteen thousand, seventeen".