665641355373 has 12 divisors (see below), whose sum is σ = 961511239260. Its totient is φ = 443747389056.

The previous prime is 665641355371. The next prime is 665641355377. The reversal of 665641355373 is 373553146566.

665641355373 is a `hidden beast` number, since 6 + 6 + 5 + 6 + 4 + 13 + 553 + 73 = 666.

665641355373 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 326547102249 + 339094253124 = 571443^2 + 582318^2 .

It is not a de Polignac number, because 665641355373 - 2¹ = 665641355371 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665641355371) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 809586 + ... + 1409507.

It is an arithmetic number, because the mean of its divisors is an integer number (80125936605).

Almost surely, 2^665641355373 is an apocalyptic number.

It is an amenable number.

665641355373 is a deficient number, since it is larger than the sum of its proper divisors (295869883887).

665641355373 is a wasteful number, since it uses less digits than its factorization.

665641355373 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2252428 (or 2252425 counting only the distinct ones).

The product of its digits is 20412000, while the sum is 54.

The spelling of 665641355373 in words is "six hundred sixty-five billion, six hundred forty-one million, three hundred fifty-five thousand, three hundred seventy-three".