688727349 has 6 divisors (see below), whose sum is σ = 994828406. Its totient is φ = 459151560.

The previous prime is 688727339. The next prime is 688727353. The reversal of 688727349 is 943727886.

It can be written as a sum of positive squares in only one way, i.e., 543356100 + 145371249 = 23310^2 + 12057^2 .

It is not a de Polignac number, because 688727349 - 2⁵ = 688727317 is a prime.

It is a super-2 number, since 2×688727349² = 948690722521135602, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 688727295 and 688727304.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688727309) 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 5 ways as a sum of consecutive naturals, for example, 38262622 + ... + 38262639.

Almost surely, 2^688727349 is an apocalyptic number.

It is an amenable number.

688727349 is a deficient number, since it is larger than the sum of its proper divisors (306101057).

688727349 is a wasteful number, since it uses less digits than its factorization.

688727349 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76525267 (or 76525264 counting only the distinct ones).

The product of its digits is 4064256, while the sum is 54.

The square root of 688727349 is about 26243.6153949870. The cubic root of 688727349 is about 883.1119800251. Note that the first 3 decimals are identical.

The spelling of 688727349 in words is "six hundred eighty-eight million, seven hundred twenty-seven thousand, three hundred forty-nine".