20811868256697 has 8 divisors (see below), whose sum is σ = 31713323057856. Its totient is φ = 11892496146672.

The previous prime is 20811868256693. The next prime is 20811868256701. The reversal of 20811868256697 is 79665286811802.

It is an interprime number because it is at equal distance from previous prime (20811868256693) and next prime (20811868256701).

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

It is not a de Polignac number, because 20811868256697 - 2² = 20811868256693 is a prime.

It is a super-2 number, since 2×20811868256697² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20811868256693) 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 7 ways as a sum of consecutive naturals, for example, 495520672758 + ... + 495520672799.

It is an arithmetic number, because the mean of its divisors is an integer number (3964165382232).

Almost surely, 2^{20811868256697} is an apocalyptic number.

It is an amenable number.

20811868256697 is a deficient number, since it is larger than the sum of its proper divisors (10901454801159).

20811868256697 is an equidigital number, since it uses as much as digits as its factorization.

20811868256697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 991041345567.

The product of its (nonzero) digits is 139345920, while the sum is 69.

The spelling of 20811868256697 in words is "twenty trillion, eight hundred eleven billion, eight hundred sixty-eight million, two hundred fifty-six thousand, six hundred ninety-seven".