666678888899 has 2 divisors, whose sum is σ = 666678888900. Its totient is φ = 666678888898.

The previous prime is 666678888851. The next prime is 666678888907. The reversal of 666678888899 is 998888876666.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666678888899 is a prime.

It is a Sophie Germain prime.

It is a plaindrome in base 10.

It is not a weakly prime, because it can be changed into another prime (666678888809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333339444449 + 333339444450.

It is an arithmetic number, because the mean of its divisors is an integer number (333339444450).

Almost surely, 2^666678888899 is an apocalyptic number.

666678888899 is a deficient number, since it is larger than the sum of its proper divisors (1).

666678888899 is an equidigital number, since it uses as much as digits as its factorization.

666678888899 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24078974976, while the sum is 89.

The spelling of 666678888899 in words is "six hundred sixty-six billion, six hundred seventy-eight million, eight hundred eighty-eight thousand, eight hundred ninety-nine".