688409064 has 256 divisors, whose sum is σ = 2377728000. Its totient is φ = 180092160.

The previous prime is 688409023. The next prime is 688409069. The reversal of 688409064 is 460904886.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (688409069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 890182 + ... + 890954.

It is an arithmetic number, because the mean of its divisors is an integer number (9288000).

Almost surely, 2^688409064 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 688409064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1188864000).

688409064 is an abundant number, since it is smaller than the sum of its proper divisors (1689318936).

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

688409064 is a wasteful number, since it uses less digits than its factorization.

688409064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 845 (or 835 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 45.

The square root of 688409064 is about 26237.5506478787. The cubic root of 688409064 is about 882.9759200844.

The spelling of 688409064 in words is "six hundred eighty-eight million, four hundred nine thousand, sixty-four".