20907766656 has 224 divisors, whose sum is σ = 71373337200. Its totient is φ = 5973460992.

The previous prime is 20907766651. The next prime is 20907766667. The reversal of 20907766656 is 65666770902.

It is a tau number, because it is divible by the number of its divisors (224).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20907766651) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 637180 + ... + 669188.

Almost surely, 2^20907766656 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 20907766656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35686668600).

20907766656 is an abundant number, since it is smaller than the sum of its proper divisors (50465570544).

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

20907766656 is an frugal number, since it uses more digits than its factorization.

20907766656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32048 (or 32021 counting only the distinct ones).

The product of its (nonzero) digits is 5715360, while the sum is 54.

The spelling of 20907766656 in words is "twenty billion, nine hundred seven million, seven hundred sixty-six thousand, six hundred fifty-six".