20666616465223 has 4 divisors (see below), whose sum is σ = 20666632074088. Its totient is φ = 20666600856360.

The previous prime is 20666616465181. The next prime is 20666616465269. The reversal of 20666616465223 is 32256461666602.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20666616465223 - 2¹⁷ = 20666616334151 is a prime.

It is a super-2 number, since 2×20666616465223² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20666616465283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5613336 + ... + 8534797.

It is an arithmetic number, because the mean of its divisors is an integer number (5166658018522).

Almost surely, 2^{20666616465223} is an apocalyptic number.

20666616465223 is a deficient number, since it is larger than the sum of its proper divisors (15608865).

20666616465223 is a wasteful number, since it uses less digits than its factorization.

20666616465223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15608864.

The product of its (nonzero) digits is 22394880, while the sum is 55.

The spelling of 20666616465223 in words is "twenty trillion, six hundred sixty-six billion, six hundred sixteen million, four hundred sixty-five thousand, two hundred twenty-three".