665718763447 has 4 divisors (see below), whose sum is σ = 665738103640. Its totient is φ = 665699423256.

The previous prime is 665718763427. The next prime is 665718763477. The reversal of 665718763447 is 744367817566.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 665718763447 - 2³⁹ = 115962949559 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 (665718763417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9618372 + ... + 9687337.

It is an arithmetic number, because the mean of its divisors is an integer number (166434525910).

Almost surely, 2^665718763447 is an apocalyptic number.

665718763447 is a deficient number, since it is larger than the sum of its proper divisors (19340193).

665718763447 is a wasteful number, since it uses less digits than its factorization.

665718763447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19340192.

The product of its digits is 142248960, while the sum is 64.

The spelling of 665718763447 in words is "six hundred sixty-five billion, seven hundred eighteen million, seven hundred sixty-three thousand, four hundred forty-seven".