1684389720 has 128 divisors (see below), whose sum is σ = 5493277440. Its totient is φ = 410703360.

The previous prime is 1684389709. The next prime is 1684389727. The reversal of 1684389720 is 279834861.

It is a self number, because there is not a number n which added to its sum of digits gives 1684389720.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1684389727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 161875 + ... + 171965.

It is an arithmetic number, because the mean of its divisors is an integer number (42916230).

Almost surely, 2^1684389720 is an apocalyptic number.

1684389720 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 1684389720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2746638720).

1684389720 is an abundant number, since it is smaller than the sum of its proper divisors (3808887720).

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

1684389720 is a wasteful number, since it uses less digits than its factorization.

1684389720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10225 (or 10221 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 48.

The square root of 1684389720 is about 41041.3172303229. The cubic root of 1684389720 is about 1189.8188929480.

The spelling of 1684389720 in words is "one billion, six hundred eighty-four million, three hundred eighty-nine thousand, seven hundred twenty".