688189741 has 4 divisors (see below), whose sum is σ = 695922300. Its totient is φ = 680457184.

The previous prime is 688189729. The next prime is 688189787. The reversal of 688189741 is 147981886.

It is a happy number.

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 347971716 + 340218025 = 18654^2 + 18445^2 .

It is a cyclic number.

It is not a de Polignac number, because 688189741 - 2⁷ = 688189613 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 (688189721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3866146 + ... + 3866323.

It is an arithmetic number, because the mean of its divisors is an integer number (173980575).

Almost surely, 2^688189741 is an apocalyptic number.

It is an amenable number.

688189741 is a deficient number, since it is larger than the sum of its proper divisors (7732559).

688189741 is an equidigital number, since it uses as much as digits as its factorization.

688189741 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7732558.

The product of its digits is 774144, while the sum is 52.

The square root of 688189741 is about 26233.3707517734. The cubic root of 688189741 is about 882.8821398465.

The spelling of 688189741 in words is "six hundred eighty-eight million, one hundred eighty-nine thousand, seven hundred forty-one".