688365641 has 4 divisors (see below), whose sum is σ = 695462292. Its totient is φ = 681268992.

The previous prime is 688365637. The next prime is 688365659. The reversal of 688365641 is 146563886.

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 149940025 + 538425616 = 12245^2 + 23204^2 .

It is a cyclic number.

It is not a de Polignac number, because 688365641 - 2² = 688365637 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (688365341) 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, 3548180 + ... + 3548373.

It is an arithmetic number, because the mean of its divisors is an integer number (173865573).

Almost surely, 2^688365641 is an apocalyptic number.

It is an amenable number.

688365641 is a deficient number, since it is larger than the sum of its proper divisors (7096651).

688365641 is an equidigital number, since it uses as much as digits as its factorization.

688365641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7096650.

The product of its digits is 829440, while the sum is 47.

The square root of 688365641 is about 26236.7231376176. The cubic root of 688365641 is about 882.9573544420.

The spelling of 688365641 in words is "six hundred eighty-eight million, three hundred sixty-five thousand, six hundred forty-one".