8209781316 has 144 divisors (see below), whose sum is σ = 22957579008. Its totient is φ = 2453068800.

The previous prime is 8209781221. The next prime is 8209781317. The reversal of 8209781316 is 6131879028.

It is not an unprimeable number, because it can be changed into a prime (8209781317) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 12126370 + ... + 12127046.

It is an arithmetic number, because the mean of its divisors is an integer number (159427632).

Almost surely, 2^8209781316 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 8209781316, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11478789504).

8209781316 is an abundant number, since it is smaller than the sum of its proper divisors (14747797692).

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

8209781316 is a wasteful number, since it uses less digits than its factorization.

8209781316 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1082 (or 1077 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 8209781316 is about 90607.8435677618. The cubic root of 8209781316 is about 2017.3311580025.

The spelling of 8209781316 in words is "eight billion, two hundred nine million, seven hundred eighty-one thousand, three hundred sixteen".