688312897 has 4 divisors (see below), whose sum is σ = 689144020. Its totient is φ = 687481776.

The previous prime is 688312861. The next prime is 688312901. The reversal of 688312897 is 798213886.

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 536431921 + 151880976 = 23161^2 + 12324^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-688312897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (688312397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 414318 + ... + 415975.

It is an arithmetic number, because the mean of its divisors is an integer number (172286005).

Almost surely, 2^688312897 is an apocalyptic number.

It is an amenable number.

688312897 is a deficient number, since it is larger than the sum of its proper divisors (831123).

688312897 is an equidigital number, since it uses as much as digits as its factorization.

688312897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 831122.

The product of its digits is 1161216, while the sum is 52.

The square root of 688312897 is about 26235.7179623505. The cubic root of 688312897 is about 882.9348025260.

The spelling of 688312897 in words is "six hundred eighty-eight million, three hundred twelve thousand, eight hundred ninety-seven".