688631040 has 324 divisors, whose sum is σ = 2512728036. Its totient is φ = 174096384.

The previous prime is 688630933. The next prime is 688631051. The reversal of 688631040 is 40136886.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 98724096 + 589906944 = 9936^2 + 24288^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 688630986 and 688631004.

It is a congruent number.

It is an unprimeable number.

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 35 ways as a sum of consecutive naturals, for example, 6094024 + ... + 6094136.

Almost surely, 2^688631040 is an apocalyptic number.

688631040 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 688631040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1256364018).

688631040 is an abundant number, since it is smaller than the sum of its proper divisors (1824096996).

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

688631040 is a wasteful number, since it uses less digits than its factorization.

688631040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186 (or 146 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 688631040 is about 26241.7804274024. The cubic root of 688631040 is about 883.0708144383.

The spelling of 688631040 in words is "six hundred eighty-eight million, six hundred thirty-one thousand, forty".