688734691 has 8 divisors (see below), whose sum is σ = 691891200. Its totient is φ = 685584840.

The previous prime is 688734677. The next prime is 688734733. The reversal of 688734691 is 196437886.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 688734691 - 2¹¹ = 688732643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (688734611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 390670 + ... + 392428.

It is an arithmetic number, because the mean of its divisors is an integer number (86486400).

Almost surely, 2^688734691 is an apocalyptic number.

688734691 is a deficient number, since it is larger than the sum of its proper divisors (3156509).

688734691 is a wasteful number, since it uses less digits than its factorization.

688734691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3329.

The product of its digits is 1741824, while the sum is 52.

The square root of 688734691 is about 26243.7552762557. The cubic root of 688734691 is about 883.1151180763.

The spelling of 688734691 in words is "six hundred eighty-eight million, seven hundred thirty-four thousand, six hundred ninety-one".