20655845671 has 4 divisors (see below), whose sum is σ = 20656741392. Its totient is φ = 20654949952.

The previous prime is 20655845669. The next prime is 20655845701. The reversal of 20655845671 is 17654855602.

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 20655845671 - 2¹ = 20655845669 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20655875671) 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, 412330 + ... + 459703.

It is an arithmetic number, because the mean of its divisors is an integer number (5164185348).

Almost surely, 2^20655845671 is an apocalyptic number.

20655845671 is a deficient number, since it is larger than the sum of its proper divisors (895721).

20655845671 is an equidigital number, since it uses as much as digits as its factorization.

20655845671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 895720.

The product of its (nonzero) digits is 2016000, while the sum is 49.

The spelling of 20655845671 in words is "twenty billion, six hundred fifty-five million, eight hundred forty-five thousand, six hundred seventy-one".