20684907776 has 108 divisors (see below), whose sum is σ = 44976012480. Its totient is φ = 9489991680.

The previous prime is 20684907769. The next prime is 20684907823. The reversal of 20684907776 is 67770948602.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7742921 + ... + 7745591.

It is an arithmetic number, because the mean of its divisors is an integer number (416444560).

Almost surely, 2^20684907776 is an apocalyptic number.

20684907776 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20684907776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22488006240).

20684907776 is an abundant number, since it is smaller than the sum of its proper divisors (24291104704).

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

20684907776 is a wasteful number, since it uses less digits than its factorization.

20684907776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2892 (or 2865 counting only the distinct ones).

The product of its (nonzero) digits is 7112448, while the sum is 56.

The spelling of 20684907776 in words is "twenty billion, six hundred eighty-four million, nine hundred seven thousand, seven hundred seventy-six".