667847989 has 8 divisors (see below), whose sum is σ = 694875960. Its totient is φ = 641086656.

The previous prime is 667847981. The next prime is 667847993. The reversal of 667847989 is 989748766.

It can be written as a sum of positive squares in 4 ways, for example, as 140778225 + 527069764 = 11865^2 + 22958^2 .

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 667847989 - 2³ = 667847981 is a prime.

It is a super-2 number, since 2×667847989² = 892041872822688242, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 667847989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667847981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61542 + ... + 71575.

It is an arithmetic number, because the mean of its divisors is an integer number (86859495).

Almost surely, 2^667847989 is an apocalyptic number.

It is an amenable number.

667847989 is a deficient number, since it is larger than the sum of its proper divisors (27027971).

667847989 is a wasteful number, since it uses less digits than its factorization.

667847989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133319.

The product of its digits is 36578304, while the sum is 64.

The square root of 667847989 is about 25842.7550582363. The cubic root of 667847989 is about 874.0961503172.

The spelling of 667847989 in words is "six hundred sixty-seven million, eight hundred forty-seven thousand, nine hundred eighty-nine".