688828505 has 8 divisors (see below), whose sum is σ = 828390024. Its totient is φ = 549865600.

The previous prime is 688828501. The next prime is 688828513. The reversal of 688828505 is 505828886.

It can be written as a sum of positive squares in 4 ways, for example, as 28955161 + 659873344 = 5381^2 + 25688^2 .

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

It is not a de Polignac number, because 688828505 - 2² = 688828501 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (688828501) 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, 147116 + ... + 151725.

It is an arithmetic number, because the mean of its divisors is an integer number (103548753).

Almost surely, 2^688828505 is an apocalyptic number.

It is an amenable number.

688828505 is a deficient number, since it is larger than the sum of its proper divisors (139561519).

688828505 is a wasteful number, since it uses less digits than its factorization.

688828505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299307.

The product of its (nonzero) digits is 1228800, while the sum is 50.

The square root of 688828505 is about 26245.5425739305. The cubic root of 688828505 is about 883.1552132448.

The spelling of 688828505 in words is "six hundred eighty-eight million, eight hundred twenty-eight thousand, five hundred five".