647807786560 has 168 divisors, whose sum is σ = 1696586766840. Its totient is φ = 235426160640.

The previous prime is 647807786557. The next prime is 647807786567. The reversal of 647807786560 is 65687708746.

It can be written as a sum of positive squares in 4 ways, for example, as 18869967424 + 628937819136 = 137368^2 + 793056^2 .

It is a Harshad number since it is a multiple of its sum of digits (64).

It is a junction number, because it is equal to n+sod(n) for n = 647807786492 and 647807786501.

It is not an unprimeable number, because it can be changed into a prime (647807786567) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 82740726 + ... + 82748554.

It is an arithmetic number, because the mean of its divisors is an integer number (10098730755).

Almost surely, 2^647807786560 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 647807786560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (848293383420).

647807786560 is an abundant number, since it is smaller than the sum of its proper divisors (1048778980280).

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

647807786560 is a wasteful number, since it uses less digits than its factorization.

647807786560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10005 (or 9984 counting only the distinct ones).

The product of its (nonzero) digits is 94832640, while the sum is 64.

The spelling of 647807786560 in words is "six hundred forty-seven billion, eight hundred seven million, seven hundred eighty-six thousand, five hundred sixty".