665555555507 has 4 divisors (see below), whose sum is σ = 666059383896. Its totient is φ = 665051727120.

The previous prime is 665555555479. The next prime is 665555555527. The reversal of 665555555507 is 705555555566.

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 665555555507 - 2²⁰ = 665554506931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665555555527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 251912213 + ... + 251914854.

It is an arithmetic number, because the mean of its divisors is an integer number (166514845974).

Almost surely, 2^665555555507 is an apocalyptic number.

665555555507 is a deficient number, since it is larger than the sum of its proper divisors (503828389).

665555555507 is a wasteful number, since it uses less digits than its factorization.

665555555507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 503828388.

The product of its (nonzero) digits is 98437500, while the sum is 59.

Adding to 665555555507 its sum of digits (59), we get a palindrome (665555555566).

The spelling of 665555555507 in words is "six hundred sixty-five billion, five hundred fifty-five million, five hundred fifty-five thousand, five hundred seven".