20969691266816 has 144 divisors (see below), whose sum is σ = 43747262697600. Its totient is φ = 10019339366400.

The previous prime is 20969691266807. The next prime is 20969691266861. The reversal of 20969691266816 is 61866219696902.

It is a self number, because there is not a number n which added to its sum of digits gives 20969691266816.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 368565731 + ... + 368622621.

It is an arithmetic number, because the mean of its divisors is an integer number (303800435400).

Almost surely, 2^{20969691266816} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20969691266816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21873631348800).

20969691266816 is an abundant number, since it is smaller than the sum of its proper divisors (22777571430784).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20969691266816 is a wasteful number, since it uses less digits than its factorization.

20969691266816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57446 (or 57432 counting only the distinct ones).

The product of its (nonzero) digits is 181398528, while the sum is 71.

The spelling of 20969691266816 in words is "twenty trillion, nine hundred sixty-nine billion, six hundred ninety-one million, two hundred sixty-six thousand, eight hundred sixteen".