20666919666945 has 8 divisors (see below), whose sum is σ = 33067071467136. Its totient is φ = 11022357155696.

The previous prime is 20666919666917. The next prime is 20666919667033. The reversal of 20666919666945 is 54966691966602.

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

It is a cyclic number.

It is not a de Polignac number, because 20666919666945 - 2¹³ = 20666919658753 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 688897322217 + ... + 688897322246.

It is an arithmetic number, because the mean of its divisors is an integer number (4133383933392).

Almost surely, 2^{20666919666945} is an apocalyptic number.

It is an amenable number.

20666919666945 is a deficient number, since it is larger than the sum of its proper divisors (12400151800191).

20666919666945 is a wasteful number, since it uses less digits than its factorization.

20666919666945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1377794644471.

The product of its (nonzero) digits is 1360488960, while the sum is 75.

The spelling of 20666919666945 in words is "twenty trillion, six hundred sixty-six billion, nine hundred nineteen million, six hundred sixty-six thousand, nine hundred forty-five".