1688541440 has 72 divisors (see below), whose sum is σ = 4074530040. Its totient is φ = 670416896.

The previous prime is 1688541433. The next prime is 1688541451. The reversal of 1688541440 is 441458861.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 713103616 + 975437824 = 26704^2 + 31232^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 170546 + ... + 180174.

It is an arithmetic number, because the mean of its divisors is an integer number (56590695).

Almost surely, 2^1688541440 is an apocalyptic number.

1688541440 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 1688541440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2037265020).

1688541440 is an abundant number, since it is smaller than the sum of its proper divisors (2385988600).

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

1688541440 is an equidigital number, since it uses as much as digits as its factorization.

1688541440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9787 (or 9773 counting only the distinct ones).

The product of its (nonzero) digits is 122880, while the sum is 41.

The square root of 1688541440 is about 41091.8658617493. The cubic root of 1688541440 is about 1190.7956546030.

The spelling of 1688541440 in words is "one billion, six hundred eighty-eight million, five hundred forty-one thousand, four hundred forty".