1688204840 has 128 divisors (see below), whose sum is σ = 4583520000. Its totient is φ = 558722304.

The previous prime is 1688204821. The next prime is 1688204849. The reversal of 1688204840 is 484028861.

It is not an unprimeable number, because it can be changed into a prime (1688204849) 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, 395759 + ... + 400001.

It is an arithmetic number, because the mean of its divisors is an integer number (35808750).

Almost surely, 2^1688204840 is an apocalyptic number.

1688204840 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 1688204840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2291760000).

1688204840 is an abundant number, since it is smaller than the sum of its proper divisors (2895315160).

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

1688204840 is a wasteful number, since it uses less digits than its factorization.

1688204840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4304 (or 4286 counting only the distinct ones).

The product of its (nonzero) digits is 98304, while the sum is 41.

The square root of 1688204840 is about 41087.7699565211. The cubic root of 1688204840 is about 1190.7165234972.

The spelling of 1688204840 in words is "one billion, six hundred eighty-eight million, two hundred four thousand, eight hundred forty".