667347831578 has 4 divisors (see below), whose sum is σ = 1001021747370. Its totient is φ = 333673915788.

The previous prime is 667347831547. The next prime is 667347831611. The reversal of 667347831578 is 875138743766.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 665475798289 + 1872033289 = 815767^2 + 43267^2 .

It is a super-3 number, since 3×667347831578³ (a number of 36 digits) contains 333 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166836957893 + ... + 166836957896.

Almost surely, 2^667347831578 is an apocalyptic number.

667347831578 is a deficient number, since it is larger than the sum of its proper divisors (333673915792).

667347831578 is a wasteful number, since it uses less digits than its factorization.

667347831578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333673915791.

The product of its digits is 142248960, while the sum is 65.

The spelling of 667347831578 in words is "six hundred sixty-seven billion, three hundred forty-seven million, eight hundred thirty-one thousand, five hundred seventy-eight".