688784040 has 256 divisors, whose sum is σ = 2709504000. Its totient is φ = 152305920.

The previous prime is 688784027. The next prime is 688784081. The reversal of 688784040 is 40487886.

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

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 232891 + ... + 235829.

It is an arithmetic number, because the mean of its divisors is an integer number (10584000).

Almost surely, 2^688784040 is an apocalyptic number.

688784040 is a gapful number since it is divisible by the number (60) 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 688784040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1354752000).

688784040 is an abundant number, since it is smaller than the sum of its proper divisors (2020719960).

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

688784040 is a wasteful number, since it uses less digits than its factorization.

688784040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2997 (or 2987 counting only the distinct ones).

The product of its (nonzero) digits is 344064, while the sum is 45.

The square root of 688784040 is about 26244.6954640362. The cubic root of 688784040 is about 883.1362098009.

The spelling of 688784040 in words is "six hundred eighty-eight million, seven hundred eighty-four thousand, forty".