1688978304 has 192 divisors, whose sum is σ = 5429227440. Its totient is φ = 519561216.

The previous prime is 1688978303. The next prime is 1688978329. The reversal of 1688978304 is 4038798861.

It is a tau number, because it is divible by the number of its divisors (192).

It is a super-2 number, since 2×1688978304² = 5705295422765432832, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1688978303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 402264 + ... + 406440.

Almost surely, 2^1688978304 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 1688978304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2714613720).

1688978304 is an abundant number, since it is smaller than the sum of its proper divisors (3740249136).

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

1688978304 is an equidigital number, since it uses as much as digits as its factorization.

1688978304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4219 (or 4195 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 54.

The square root of 1688978304 is about 41097.1812172076. The cubic root of 1688978304 is about 1190.8983410366.

The spelling of 1688978304 in words is "one billion, six hundred eighty-eight million, nine hundred seventy-eight thousand, three hundred four".