665380757815 has 16 divisors (see below), whose sum is σ = 840502350720. Its totient is φ = 504275738400.

The previous prime is 665380757801. The next prime is 665380757849. The reversal of 665380757815 is 518757083566.

It is a happy number.

It is not a de Polignac number, because 665380757815 - 2¹⁹ = 665380233527 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5492932 + ... + 5612758.

It is an arithmetic number, because the mean of its divisors is an integer number (52531396920).

Almost surely, 2^665380757815 is an apocalyptic number.

665380757815 is a deficient number, since it is larger than the sum of its proper divisors (175121592905).

665380757815 is a wasteful number, since it uses less digits than its factorization.

665380757815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178302.

The product of its (nonzero) digits is 42336000, while the sum is 61.

The spelling of 665380757815 in words is "six hundred sixty-five billion, three hundred eighty million, seven hundred fifty-seven thousand, eight hundred fifteen".