71315665 has 4 divisors (see below), whose sum is σ = 85578804. Its totient is φ = 57052528.

The previous prime is 71315653. The next prime is 71315681. The reversal of 71315665 is 56651317.

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 44782864 + 26532801 = 6692^2 + 5151^2 .

It is a cyclic number.

It is not a de Polignac number, because 71315665 - 2⁵ = 71315633 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 71315665.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7131562 + ... + 7131571.

It is an arithmetic number, because the mean of its divisors is an integer number (21394701).

Almost surely, 2^71315665 is an apocalyptic number.

It is an amenable number.

71315665 is a deficient number, since it is larger than the sum of its proper divisors (14263139).

71315665 is a wasteful number, since it uses less digits than its factorization.

71315665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14263138.

The product of its digits is 18900, while the sum is 34.

The square root of 71315665 is about 8444.8602711945. The cubic root of 71315665 is about 414.6945349764.

The spelling of 71315665 in words is "seventy-one million, three hundred fifteen thousand, six hundred sixty-five".