20782448640 has 544 divisors, whose sum is σ = 77384318400. Its totient is φ = 5350883328.

The previous prime is 20782448593. The next prime is 20782448647. The reversal of 20782448640 is 4684428702.

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

It is not an unprimeable number, because it can be changed into a prime (20782448647) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 716636146 + ... + 716636174.

Almost surely, 2^20782448640 is an apocalyptic number.

20782448640 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 20782448640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38692159200).

20782448640 is an abundant number, since it is smaller than the sum of its proper divisors (56601869760).

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

20782448640 is an frugal number, since it uses more digits than its factorization.

20782448640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87 (or 39 counting only the distinct ones).

The product of its (nonzero) digits is 688128, while the sum is 45.

The spelling of 20782448640 in words is "twenty billion, seven hundred eighty-two million, four hundred forty-eight thousand, six hundred forty".