688091436 has 108 divisors (see below), whose sum is σ = 1828536528. Its totient is φ = 226538208.

The previous prime is 688091429. The next prime is 688091449. The reversal of 688091436 is 634190886.

It is a tau number, because it is divible by the number of its divisors (108).

It is a junction number, because it is equal to n+sod(n) for n = 688091391 and 688091400.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 4120225 + ... + 4120391.

Almost surely, 2^688091436 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 688091436, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (914268264).

688091436 is an abundant number, since it is smaller than the sum of its proper divisors (1140445092).

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

688091436 is a wasteful number, since it uses less digits than its factorization.

688091436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352 (or 329 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The square root of 688091436 is about 26231.4970217104. The cubic root of 688091436 is about 882.8400991822.

The spelling of 688091436 in words is "six hundred eighty-eight million, ninety-one thousand, four hundred thirty-six".