20209821788856 has 64 divisors (see below), whose sum is σ = 57744998599680. Its totient is φ = 5773969733760.

The previous prime is 20209821788843. The next prime is 20209821788873. The reversal of 20209821788856 is 65888712890202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 924190 + ... + 6424466.

It is an arithmetic number, because the mean of its divisors is an integer number (902265603120).

Almost surely, 2^{20209821788856} is an apocalyptic number.

It is an amenable number.

20209821788856 is an abundant number, since it is smaller than the sum of its proper divisors (37535176810824).

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

20209821788856 is a wasteful number, since it uses less digits than its factorization.

20209821788856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5522164 (or 5522160 counting only the distinct ones).

The product of its (nonzero) digits is 61931520, while the sum is 66.

The spelling of 20209821788856 in words is "twenty trillion, two hundred nine billion, eight hundred twenty-one million, seven hundred eighty-eight thousand, eight hundred fifty-six".