666785688897 has 32 divisors (see below), whose sum is σ = 913054413312. Its totient is φ = 432628383744.

The previous prime is 666785688889. The next prime is 666785688929. The reversal of 666785688897 is 798886587666.

666785688897 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 666785688897 - 2³ = 666785688889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (666785688817) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 98970313 + ... + 98977049.

It is an arithmetic number, because the mean of its divisors is an integer number (28532950416).

Almost surely, 2^666785688897 is an apocalyptic number.

It is an amenable number.

666785688897 is a deficient number, since it is larger than the sum of its proper divisors (246268724415).

666785688897 is a wasteful number, since it uses less digits than its factorization.

666785688897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10617.

The product of its digits is 11705057280, while the sum is 84.

It can be divided in two parts, 66678 and 5688897, that added together give a palindrome (5755575).

The spelling of 666785688897 in words is "six hundred sixty-six billion, seven hundred eighty-five million, six hundred eighty-eight thousand, eight hundred ninety-seven".