688271321 has 2 divisors, whose sum is σ = 688271322. Its totient is φ = 688271320.

The previous prime is 688271317. The next prime is 688271323. The reversal of 688271321 is 123172886.

688271321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 628053721 + 60217600 = 25061^2 + 7760^2 .

It is a cyclic number.

It is not a de Polignac number, because 688271321 - 2² = 688271317 is a prime.

It is a super-2 number, since 2×688271321² = 947434822622170082, which contains 22 as substring.

Together with 688271323, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (688271323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344135660 + 344135661.

It is an arithmetic number, because the mean of its divisors is an integer number (344135661).

Almost surely, 2^688271321 is an apocalyptic number.

It is an amenable number.

688271321 is a deficient number, since it is larger than the sum of its proper divisors (1).

688271321 is an equidigital number, since it uses as much as digits as its factorization.

688271321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32256, while the sum is 38.

The square root of 688271321 is about 26234.9255954729. The cubic root of 688271321 is about 882.9170249345.

The spelling of 688271321 in words is "six hundred eighty-eight million, two hundred seventy-one thousand, three hundred twenty-one".