667722721205 has 8 divisors (see below), whose sum is σ = 806644899000. Its totient is φ = 530593087936.

The previous prime is 667722721187. The next prime is 667722721207. The reversal of 667722721205 is 502127227766.

It can be written as a sum of positive squares in 4 ways, for example, as 1486410916 + 666236310289 = 38554^2 + 816233^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 667722721205 - 2³² = 663427753909 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 667722721205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667722721207) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 448135310 + ... + 448136799.

It is an arithmetic number, because the mean of its divisors is an integer number (100830612375).

Almost surely, 2^667722721205 is an apocalyptic number.

It is an amenable number.

667722721205 is a deficient number, since it is larger than the sum of its proper divisors (138922177795).

667722721205 is a wasteful number, since it uses less digits than its factorization.

667722721205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 896272263.

The product of its (nonzero) digits is 987840, while the sum is 47.

The spelling of 667722721205 in words is "six hundred sixty-seven billion, seven hundred twenty-two million, seven hundred twenty-one thousand, two hundred five".