66888989899 has 2 divisors, whose sum is σ = 66888989900. Its totient is φ = 66888989898.

The previous prime is 66888989801. The next prime is 66888989917. The reversal of 66888989899 is 99898988866.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66888989899 is a prime.

It is not a weakly prime, because it can be changed into another prime (66888989099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33444494949 + 33444494950.

It is an arithmetic number, because the mean of its divisors is an integer number (33444494950).

Almost surely, 2^66888989899 is an apocalyptic number.

66888989899 is a deficient number, since it is larger than the sum of its proper divisors (1).

66888989899 is an equidigital number, since it uses as much as digits as its factorization.

66888989899 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7739670528, while the sum is 88.

The spelling of 66888989899 in words is "sixty-six billion, eight hundred eighty-eight million, nine hundred eighty-nine thousand, eight hundred ninety-nine".