1688064840 has 512 divisors, whose sum is σ = 7166361600. Its totient is φ = 343249920.

The previous prime is 1688064743. The next prime is 1688064841. The reversal of 1688064840 is 484608861.

1688064840 is a `hidden beast` number, since 168 + 8 + 0 + 6 + 484 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (1688064841) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 4407289 + ... + 4407671.

It is an arithmetic number, because the mean of its divisors is an integer number (13996800).

Almost surely, 2^1688064840 is an apocalyptic number.

1688064840 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 1688064840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3583180800).

1688064840 is an abundant number, since it is smaller than the sum of its proper divisors (5478296760).

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

1688064840 is a wasteful number, since it uses less digits than its factorization.

1688064840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 474 (or 464 counting only the distinct ones).

The product of its (nonzero) digits is 294912, while the sum is 45.

The square root of 1688064840 is about 41086.0662512244. The cubic root of 1688064840 is about 1190.6836078782.

The spelling of 1688064840 in words is "one billion, six hundred eighty-eight million, sixty-four thousand, eight hundred forty".