667812825909 has 20 divisors (see below), whose sum is σ = 1001305508940. Its totient is φ = 443553485760.

The previous prime is 667812825853. The next prime is 667812825923. The reversal of 667812825909 is 909528218766.

It can be written as a sum of positive squares in 2 ways, for example, as 80796357009 + 587016468900 = 284247^2 + 766170^2 .

It is not a de Polignac number, because 667812825909 - 2²⁰ = 667811777333 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667812825929) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 15302752 + ... + 15346329.

It is an arithmetic number, because the mean of its divisors is an integer number (50065275447).

Almost surely, 2^667812825909 is an apocalyptic number.

It is an amenable number.

667812825909 is a deficient number, since it is larger than the sum of its proper divisors (333492683031).

667812825909 is a wasteful number, since it uses less digits than its factorization.

667812825909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30649362 (or 30649353 counting only the distinct ones).

The product of its (nonzero) digits is 26127360, while the sum is 63.

The spelling of 667812825909 in words is "six hundred sixty-seven billion, eight hundred twelve million, eight hundred twenty-five thousand, nine hundred nine".