20665839744 has 864 divisors, whose sum is σ = 75798668400. Its totient is φ = 5583790080.

The previous prime is 20665839731. The next prime is 20665839749. The reversal of 20665839744 is 44793856602.

20665839744 is a `hidden beast` number, since 206 + 6 + 5 + 8 + 397 + 44 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (20665839749) by changing a digit.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 1087675767 + ... + 1087675785.

Almost surely, 2^20665839744 is an apocalyptic number.

20665839744 is a gapful number since it is divisible by the number (24) 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 20665839744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37899334200).

20665839744 is an abundant number, since it is smaller than the sum of its proper divisors (55132828656).

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

20665839744 is a wasteful number, since it uses less digits than its factorization.

20665839744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104 (or 52 counting only the distinct ones).

The product of its (nonzero) digits is 8709120, while the sum is 54.

The spelling of 20665839744 in words is "twenty billion, six hundred sixty-five million, eight hundred thirty-nine thousand, seven hundred forty-four".