20505666216707 has 32 divisors (see below), whose sum is σ = 24701889676800. Its totient is φ = 16628674664448.

The previous prime is 20505666216689. The next prime is 20505666216733. The reversal of 20505666216707 is 70761266650502.

It is a happy number.

It is not a de Polignac number, because 20505666216707 - 2¹⁶ = 20505666151171 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20505666216767) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 312844544 + ... + 312910082.

It is an arithmetic number, because the mean of its divisors is an integer number (771934052400).

Almost surely, 2^{20505666216707} is an apocalyptic number.

20505666216707 is a deficient number, since it is larger than the sum of its proper divisors (4196223460093).

20505666216707 is a wasteful number, since it uses less digits than its factorization.

20505666216707 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68715.

The product of its (nonzero) digits is 6350400, while the sum is 53.

The spelling of 20505666216707 in words is "twenty trillion, five hundred five billion, six hundred sixty-six million, two hundred sixteen thousand, seven hundred seven".