667565612557 has 4 divisors (see below), whose sum is σ = 667593459900. Its totient is φ = 667537765216.

The previous prime is 667565612501. The next prime is 667565612563. The reversal of 667565612557 is 755216565766.

667565612557 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 can be written as a sum of positive squares in 2 ways, for example, as 225614550121 + 441951062436 = 474989^2 + 664794^2 .

It is a cyclic number.

It is not a de Polignac number, because 667565612557 - 2¹⁹ = 667565088269 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 667565612495 and 667565612504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667565612057) 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, 13887682 + ... + 13935667.

It is an arithmetic number, because the mean of its divisors is an integer number (166898364975).

Almost surely, 2^667565612557 is an apocalyptic number.

It is an amenable number.

667565612557 is a deficient number, since it is larger than the sum of its proper divisors (27847343).

667565612557 is a wasteful number, since it uses less digits than its factorization.

667565612557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27847342.

The product of its digits is 79380000, while the sum is 61.

The spelling of 667565612557 in words is "six hundred sixty-seven billion, five hundred sixty-five million, six hundred twelve thousand, five hundred fifty-seven".