667667661268 has 6 divisors (see below), whose sum is σ = 1168418407226. Its totient is φ = 333833830632.

The previous prime is 667667661263. The next prime is 667667661277. The reversal of 667667661268 is 862166766766.

It can be written as a sum of positive squares in only one way, i.e., 534071563204 + 133596098064 = 730802^2 + 365508^2 .

It is a super-3 number, since 3×667667661268³ (a number of 36 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667667661263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83458457655 + ... + 83458457662.

Almost surely, 2^667667661268 is an apocalyptic number.

It is an amenable number.

667667661268 is a deficient number, since it is larger than the sum of its proper divisors (500750745958).

667667661268 is a wasteful number, since it uses less digits than its factorization.

667667661268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166916915321 (or 166916915319 counting only the distinct ones).

The product of its digits is 219469824, while the sum is 67.

The spelling of 667667661268 in words is "six hundred sixty-seven billion, six hundred sixty-seven million, six hundred sixty-one thousand, two hundred sixty-eight".