21713982770855 has 4 divisors (see below), whose sum is σ = 26056779325032. Its totient is φ = 17371186216680.

The previous prime is 21713982770789. The next prime is 21713982770897. The reversal of 21713982770855 is 55807728931712.

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

It is a de Polignac number, because none of the positive numbers 2^k-21713982770855 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21713982770791 and 21713982770800.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2171398277081 + ... + 2171398277090.

It is an arithmetic number, because the mean of its divisors is an integer number (6514194831258).

Almost surely, 2^{21713982770855} is an apocalyptic number.

21713982770855 is a deficient number, since it is larger than the sum of its proper divisors (4342796554177).

21713982770855 is an equidigital number, since it uses as much as digits as its factorization.

21713982770855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4342796554176.

The product of its (nonzero) digits is 59270400, while the sum is 65.

The spelling of 21713982770855 in words is "twenty-one trillion, seven hundred thirteen billion, nine hundred eighty-two million, seven hundred seventy thousand, eight hundred fifty-five".