667688535428 has 6 divisors (see below), whose sum is σ = 1168454937006. Its totient is φ = 333844267712.

The previous prime is 667688535421. The next prime is 667688535431. The reversal of 667688535428 is 824535886766.

It can be written as a sum of positive squares in only one way, i.e., 630559870084 + 37128665344 = 794078^2 + 192688^2 .

It is a super-2 number, since 2×667688535428² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (667688535421) by changing a digit.

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, 83461066925 + ... + 83461066932.

It is an arithmetic number, because the mean of its divisors is an integer number (194742489501).

Almost surely, 2^667688535428 is an apocalyptic number.

It is an amenable number.

667688535428 is a deficient number, since it is larger than the sum of its proper divisors (500766401578).

667688535428 is a wasteful number, since it uses less digits than its factorization.

667688535428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166922133861 (or 166922133859 counting only the distinct ones).

The product of its digits is 464486400, while the sum is 68.

The spelling of 667688535428 in words is "six hundred sixty-seven billion, six hundred eighty-eight million, five hundred thirty-five thousand, four hundred twenty-eight".