121720661066 has 8 divisors (see below), whose sum is σ = 183175718880. Its totient is φ = 60662088108.

The previous prime is 121720661063. The next prime is 121720661071. The reversal of 121720661066 is 660166027121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (121720661063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99120446 + ... + 99121673.

It is an arithmetic number, because the mean of its divisors is an integer number (22896964860).

Almost surely, 2^121720661066 is an apocalyptic number.

121720661066 is a deficient number, since it is larger than the sum of its proper divisors (61455057814).

121720661066 is a wasteful number, since it uses less digits than its factorization.

121720661066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198242428.

The product of its (nonzero) digits is 36288, while the sum is 38.

Adding to 121720661066 its reverse (660166027121), we get a palindrome (781886688187).

The spelling of 121720661066 in words is "one hundred twenty-one billion, seven hundred twenty million, six hundred sixty-one thousand, sixty-six".