688103640 has 128 divisors (see below), whose sum is σ = 2621376000. Its totient is φ = 157279104.

The previous prime is 688103629. The next prime is 688103657. The reversal of 688103640 is 46301886.

It is a happy number.

688103640 is a `hidden beast` number, since 6 + 8 + 8 + 1 + 0 + 3 + 640 = 666.

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 = 688103595 and 688103604.

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 31 ways as a sum of consecutive naturals, for example, 37950 + ... + 53069.

It is an arithmetic number, because the mean of its divisors is an integer number (20479500).

Almost surely, 2^688103640 is an apocalyptic number.

688103640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

688103640 is an abundant number, since it is smaller than the sum of its proper divisors (1933272360).

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

688103640 is a wasteful number, since it uses less digits than its factorization.

688103640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91046 (or 91036 counting only the distinct ones).

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

The square root of 688103640 is about 26231.7296417907. The cubic root of 688103640 is about 882.8453185064.

The spelling of 688103640 in words is "six hundred eighty-eight million, one hundred three thousand, six hundred forty".