688137678 has 12 divisors (see below), whose sum is σ = 1490965008. Its totient is φ = 229379220.

The previous prime is 688137677. The next prime is 688137683. The reversal of 688137678 is 876731886.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688137673) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 19114918 + ... + 19114953.

It is an arithmetic number, because the mean of its divisors is an integer number (124247084).

Almost surely, 2^688137678 is an apocalyptic number.

688137678 is an abundant number, since it is smaller than the sum of its proper divisors (802827330).

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

688137678 is a wasteful number, since it uses less digits than its factorization.

688137678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38229879 (or 38229876 counting only the distinct ones).

The product of its digits is 2709504, while the sum is 54.

The square root of 688137678 is about 26232.3784281944. The cubic root of 688137678 is about 882.8598753220.

The spelling of 688137678 in words is "six hundred eighty-eight million, one hundred thirty-seven thousand, six hundred seventy-eight".