1686844380 has 192 divisors, whose sum is σ = 5620866048. Its totient is φ = 373739520.

The previous prime is 1686844351. The next prime is 1686844387. The reversal of 1686844380 is 834486861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1686844387) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 302215 + ... + 307745.

It is an arithmetic number, because the mean of its divisors is an integer number (29275344).

Almost surely, 2^1686844380 is an apocalyptic number.

1686844380 is a gapful number since it is divisible by the number (10) 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 1686844380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2810433024).

1686844380 is an abundant number, since it is smaller than the sum of its proper divisors (3934021668).

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

1686844380 is a wasteful number, since it uses less digits than its factorization.

1686844380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5596 (or 5594 counting only the distinct ones).

The product of its (nonzero) digits is 884736, while the sum is 48.

The square root of 1686844380 is about 41071.2110851385. The cubic root of 1686844380 is about 1190.3965865040.

The spelling of 1686844380 in words is "one billion, six hundred eighty-six million, eight hundred forty-four thousand, three hundred eighty".