688194469 has 2 divisors, whose sum is σ = 688194470. Its totient is φ = 688194468.

The previous prime is 688194449. The next prime is 688194491. The reversal of 688194469 is 964491886.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 684450244 + 3744225 = 26162^2 + 1935^2 .

It is a cyclic number.

It is not a de Polignac number, because 688194469 - 2⁷ = 688194341 is a prime.

It is a super-2 number, since 2×688194469² = 947223254324383922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688194439) 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 as a sum of consecutive naturals, namely, 344097234 + 344097235.

It is an arithmetic number, because the mean of its divisors is an integer number (344097235).

Almost surely, 2^688194469 is an apocalyptic number.

It is an amenable number.

688194469 is a deficient number, since it is larger than the sum of its proper divisors (1).

688194469 is an equidigital number, since it uses as much as digits as its factorization.

688194469 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2985984, while the sum is 55.

The square root of 688194469 is about 26233.4608658484. The cubic root of 688194469 is about 882.8841617003.

The spelling of 688194469 in words is "six hundred eighty-eight million, one hundred ninety-four thousand, four hundred sixty-nine".