20688248666 has 16 divisors (see below), whose sum is σ = 31818793248. Its totient is φ = 10082965200.

The previous prime is 20688248663. The next prime is 20688248681. The reversal of 20688248666 is 66684288602.

It is not an unprimeable number, because it can be changed into a prime (20688248663) 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 7 ways as a sum of consecutive naturals, for example, 202745 + ... + 287196.

It is an arithmetic number, because the mean of its divisors is an integer number (1988674578).

Almost surely, 2^20688248666 is an apocalyptic number.

20688248666 is a deficient number, since it is larger than the sum of its proper divisors (11130544582).

20688248666 is a wasteful number, since it uses less digits than its factorization.

20688248666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 490477.

The product of its (nonzero) digits is 10616832, while the sum is 56.

The spelling of 20688248666 in words is "twenty billion, six hundred eighty-eight million, two hundred forty-eight thousand, six hundred sixty-six".