667278637673 has 4 divisors (see below), whose sum is σ = 706530322260. Its totient is φ = 628026953088.

The previous prime is 667278637667. The next prime is 667278637717. The reversal of 667278637673 is 376736872766.

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 515305751104 + 151972886569 = 717848^2 + 389837^2 .

It is a cyclic number.

It is not a de Polignac number, because 667278637673 - 2¹⁶ = 667278572137 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (667278337673) 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, 19625842268 + ... + 19625842301.

It is an arithmetic number, because the mean of its divisors is an integer number (176632580565).

Almost surely, 2^667278637673 is an apocalyptic number.

It is an amenable number.

667278637673 is a deficient number, since it is larger than the sum of its proper divisors (39251684587).

667278637673 is a wasteful number, since it uses less digits than its factorization.

667278637673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39251684586.

The product of its digits is 448084224, while the sum is 68.

The spelling of 667278637673 in words is "six hundred sixty-seven billion, two hundred seventy-eight million, six hundred thirty-seven thousand, six hundred seventy-three".