20686880399856 has 160 divisors (see below), whose sum is σ = 60224104267776. Its totient is φ = 6062089440000.

The previous prime is 20686880399821. The next prime is 20686880399881. The reversal of 20686880399856 is 65899308868602.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 21912781 + ... + 22837331.

Almost surely, 2^{20686880399856} 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 20686880399856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30112052133888).

20686880399856 is an abundant number, since it is smaller than the sum of its proper divisors (39537223867920).

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

20686880399856 is a wasteful number, since it uses less digits than its factorization.

20686880399856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 925971 (or 925965 counting only the distinct ones).

The product of its (nonzero) digits is 2149908480, while the sum is 78.

The spelling of 20686880399856 in words is "twenty trillion, six hundred eighty-six billion, eight hundred eighty million, three hundred ninety-nine thousand, eight hundred fifty-six".