688840947 has 12 divisors (see below), whose sum is σ = 1013766624. Its totient is φ = 450562320.

The previous prime is 688840937. The next prime is 688840993. The reversal of 688840947 is 749048886.

688840947 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 688840947 - 2¹² = 688836851 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 688840893 and 688840902.

It is not an unprimeable number, because it can be changed into a prime (688840937) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 721579 + ... + 722532.

It is an arithmetic number, because the mean of its divisors is an integer number (84480552).

Almost surely, 2^688840947 is an apocalyptic number.

688840947 is a deficient number, since it is larger than the sum of its proper divisors (324925677).

688840947 is a wasteful number, since it uses less digits than its factorization.

688840947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1444170 (or 1444167 counting only the distinct ones).

The product of its (nonzero) digits is 3096576, while the sum is 54.

The square root of 688840947 is about 26245.7796035858. The cubic root of 688840947 is about 883.1605305581.

The spelling of 688840947 in words is "six hundred eighty-eight million, eight hundred forty thousand, nine hundred forty-seven".