688178646 has 16 divisors (see below), whose sum is σ = 1529286000. Its totient is φ = 229392864.

The previous prime is 688178639. The next prime is 688178657. The reversal of 688178646 is 646871886.

It is a Harshad number since it is a multiple of its sum of digits (54), and also a Moran number because the ratio is a prime number: 12744049 = 688178646 / (6 + 8 + 8 + 1 + 7 + 8 + 6 + 4 + 6).

It is a junction number, because it is equal to n+sod(n) for n = 688178592 and 688178601.

It is a congruent number.

It is an unprimeable number.

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, 6371971 + ... + 6372078.

It is an arithmetic number, because the mean of its divisors is an integer number (95580375).

Almost surely, 2^688178646 is an apocalyptic number.

688178646 is an abundant number, since it is smaller than the sum of its proper divisors (841107354).

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

688178646 is a wasteful number, since it uses less digits than its factorization.

688178646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12744060 (or 12744054 counting only the distinct ones).

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

The square root of 688178646 is about 26233.1592836242. The cubic root of 688178646 is about 882.8773952102.

The spelling of 688178646 in words is "six hundred eighty-eight million, one hundred seventy-eight thousand, six hundred forty-six".