667888889909 has 2 divisors, whose sum is σ = 667888889910. Its totient is φ = 667888889908.

The previous prime is 667888889873. The next prime is 667888889951. The reversal of 667888889909 is 909988888766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 653990837809 + 13898052100 = 808697^2 + 117890^2 .

It is a cyclic number.

It is not a de Polignac number, because 667888889909 - 2⁸ = 667888889653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (667888889999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333944444954 + 333944444955.

It is an arithmetic number, because the mean of its divisors is an integer number (333944444955).

Almost surely, 2^667888889909 is an apocalyptic number.

It is an amenable number.

667888889909 is a deficient number, since it is larger than the sum of its proper divisors (1).

667888889909 is an equidigital number, since it uses as much as digits as its factorization.

667888889909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6019743744, while the sum is 86.

The spelling of 667888889909 in words is "six hundred sixty-seven billion, eight hundred eighty-eight million, eight hundred eighty-nine thousand, nine hundred nine".