688467891 has 32 divisors (see below), whose sum is σ = 957846528. Its totient is φ = 439568640.

The previous prime is 688467851. The next prime is 688467893. The reversal of 688467891 is 198764886.

688467891 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 688467891 - 2¹⁴ = 688451507 is a prime.

It is not an unprimeable number, because it can be changed into a prime (688467893) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2171665 + ... + 2171981.

It is an arithmetic number, because the mean of its divisors is an integer number (29932704).

Almost surely, 2^688467891 is an apocalyptic number.

688467891 is a deficient number, since it is larger than the sum of its proper divisors (269378637).

688467891 is a wasteful number, since it uses less digits than its factorization.

688467891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 651.

The product of its digits is 4644864, while the sum is 57.

The square root of 688467891 is about 26238.6716698845. The cubic root of 688467891 is about 883.0010705110.

The spelling of 688467891 in words is "six hundred eighty-eight million, four hundred sixty-seven thousand, eight hundred ninety-one".