665660477571 has 4 divisors (see below), whose sum is σ = 887547303432. Its totient is φ = 443773651712.

The previous prime is 665660477569. The next prime is 665660477597. The reversal of 665660477571 is 175774066566.

665660477571 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 665660477571 - 2¹ = 665660477569 is a prime.

It is not an unprimeable number, because it can be changed into a prime (665660477371) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110943412926 + ... + 110943412931.

It is an arithmetic number, because the mean of its divisors is an integer number (221886825858).

Almost surely, 2^665660477571 is an apocalyptic number.

665660477571 is a deficient number, since it is larger than the sum of its proper divisors (221886825861).

665660477571 is a wasteful number, since it uses less digits than its factorization.

665660477571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221886825860.

The product of its (nonzero) digits is 44452800, while the sum is 60.

The spelling of 665660477571 in words is "six hundred sixty-five billion, six hundred sixty million, four hundred seventy-seven thousand, five hundred seventy-one".