667728478187 has 2 divisors, whose sum is σ = 667728478188. Its totient is φ = 667728478186.

The previous prime is 667728478181. The next prime is 667728478211. The reversal of 667728478187 is 781874827766.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 667728478187 - 2⁴ = 667728478171 is a prime.

It is a super-2 number, since 2×667728478187² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 667728478187.

It is not a weakly prime, because it can be changed into another prime (667728478181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333864239093 + 333864239094.

It is an arithmetic number, because the mean of its divisors is an integer number (333864239094).

Almost surely, 2^667728478187 is an apocalyptic number.

667728478187 is a deficient number, since it is larger than the sum of its proper divisors (1).

667728478187 is an equidigital number, since it uses as much as digits as its factorization.

667728478187 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 354041856, while the sum is 71.

The spelling of 667728478187 in words is "six hundred sixty-seven billion, seven hundred twenty-eight million, four hundred seventy-eight thousand, one hundred eighty-seven".