20912845680 has 200 divisors, whose sum is σ = 75791925792. Its totient is φ = 5334253056.

The previous prime is 20912845663. The next prime is 20912845693. The reversal of 20912845680 is 8654821902.

20912845680 is a `hidden beast` number, since 2 + 0 + 9 + 1 + 2 + 84 + 568 + 0 = 666.

It is a super-2 number, since 2×20912845680² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 78882 + ... + 219198.

Almost surely, 2^20912845680 is an apocalyptic number.

20912845680 is a gapful number since it is divisible by the number (20) 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 20912845680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37895962896).

20912845680 is an abundant number, since it is smaller than the sum of its proper divisors (54879080112).

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

20912845680 is a wasteful number, since it uses less digits than its factorization.

20912845680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140365 (or 140350 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The spelling of 20912845680 in words is "twenty billion, nine hundred twelve million, eight hundred forty-five thousand, six hundred eighty".