688515085 has 4 divisors (see below), whose sum is σ = 826218108. Its totient is φ = 550812064.

The previous prime is 688515083. The next prime is 688515101. The reversal of 688515085 is 580515886.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 101082916 + 587432169 = 10054^2 + 24237^2 .

It is a cyclic number.

It is not a de Polignac number, because 688515085 - 2¹ = 688515083 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688515083) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68851504 + ... + 68851513.

It is an arithmetic number, because the mean of its divisors is an integer number (206554527).

Almost surely, 2^688515085 is an apocalyptic number.

It is an amenable number.

688515085 is a deficient number, since it is larger than the sum of its proper divisors (137703023).

688515085 is a wasteful number, since it uses less digits than its factorization.

688515085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137703022.

The product of its (nonzero) digits is 384000, while the sum is 46.

The square root of 688515085 is about 26239.5709759135. The cubic root of 688515085 is about 883.0212464218.

The spelling of 688515085 in words is "six hundred eighty-eight million, five hundred fifteen thousand, eighty-five".