688128125 has 24 divisors (see below), whose sum is σ = 910769832. Its totient is φ = 518080000.

The previous prime is 688128113. The next prime is 688128131. The reversal of 688128125 is 521821886.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 686335204 + 1792921 = 26198^2 + 1339^2 .

It is not a de Polignac number, because 688128125 - 2⁶ = 688128061 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 46649 + ... + 59601.

It is an arithmetic number, because the mean of its divisors is an integer number (37948743).

Almost surely, 2^688128125 is an apocalyptic number.

It is an amenable number.

688128125 is a deficient number, since it is larger than the sum of its proper divisors (222641707).

688128125 is an equidigital number, since it uses as much as digits as its factorization.

688128125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12995 (or 12975 counting only the distinct ones).

The product of its digits is 61440, while the sum is 41.

The square root of 688128125 is about 26232.1963434250. The cubic root of 688128125 is about 882.8557898995.

The spelling of 688128125 in words is "six hundred eighty-eight million, one hundred twenty-eight thousand, one hundred twenty-five".