66918123788 has 6 divisors (see below), whose sum is σ = 117106716636. Its totient is φ = 33459061892.

The previous prime is 66918123763. The next prime is 66918123799. The reversal of 66918123788 is 88732181966.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8364765470 + ... + 8364765477.

It is an arithmetic number, because the mean of its divisors is an integer number (19517786106).

Almost surely, 2^66918123788 is an apocalyptic number.

It is an amenable number.

66918123788 is a deficient number, since it is larger than the sum of its proper divisors (50188592848).

66918123788 is a wasteful number, since it uses less digits than its factorization.

66918123788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16729530951 (or 16729530949 counting only the distinct ones).

The product of its digits is 6967296, while the sum is 59.

The spelling of 66918123788 in words is "sixty-six billion, nine hundred eighteen million, one hundred twenty-three thousand, seven hundred eighty-eight".