71640666692647 has 16 divisors (see below), whose sum is σ = 79848006430752. Its totient is φ = 63851800135680.

The previous prime is 71640666692537. The next prime is 71640666692657. The reversal of 71640666692647 is 74629666604617.

It is a cyclic number.

It is not a de Polignac number, because 71640666692647 - 2¹⁹ = 71640666168359 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71640666692657) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 692784673 + ... + 692888074.

It is an arithmetic number, because the mean of its divisors is an integer number (4990500401922).

Almost surely, 2^{71640666692647} is an apocalyptic number.

71640666692647 is a deficient number, since it is larger than the sum of its proper divisors (8207339738105).

71640666692647 is a wasteful number, since it uses less digits than its factorization.

71640666692647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1385672898.

The product of its (nonzero) digits is 658409472, while the sum is 70.

The spelling of 71640666692647 in words is "seventy-one trillion, six hundred forty billion, six hundred sixty-six million, six hundred ninety-two thousand, six hundred forty-seven".