71615365681 has 4 divisors (see below), whose sum is σ = 72284668272. Its totient is φ = 70946063092.

The previous prime is 71615365669. The next prime is 71615365721. The reversal of 71615365681 is 18656351617.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 71615365681 - 2⁹ = 71615365169 is a prime.

It is a super-2 number, since 2×71615365681² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71615365631) 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, 334651135 + ... + 334651348.

It is an arithmetic number, because the mean of its divisors is an integer number (18071167068).

Almost surely, 2^71615365681 is an apocalyptic number.

It is an amenable number.

71615365681 is a deficient number, since it is larger than the sum of its proper divisors (669302591).

71615365681 is a wasteful number, since it uses less digits than its factorization.

71615365681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 669302590.

The product of its digits is 907200, while the sum is 49.

The spelling of 71615365681 in words is "seventy-one billion, six hundred fifteen million, three hundred sixty-five thousand, six hundred eighty-one".