688561085 has 8 divisors (see below), whose sum is σ = 826416600. Its totient is φ = 550753344.

The previous prime is 688561031. The next prime is 688561087. The reversal of 688561085 is 580165886.

It can be written as a sum of positive squares in 4 ways, for example, as 352425529 + 336135556 = 18773^2 + 18334^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-688561085 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688561087) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41591 + ... + 55739.

It is an arithmetic number, because the mean of its divisors is an integer number (103302075).

Almost surely, 2^688561085 is an apocalyptic number.

It is an amenable number.

688561085 is a deficient number, since it is larger than the sum of its proper divisors (137855515).

688561085 is a wasteful number, since it uses less digits than its factorization.

688561085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23887.

The product of its (nonzero) digits is 460800, while the sum is 47.

The square root of 688561085 is about 26240.4474999951. The cubic root of 688561085 is about 883.0409109984.

The spelling of 688561085 in words is "six hundred eighty-eight million, five hundred sixty-one thousand, eighty-five".