689749321 has 2 divisors, whose sum is σ = 689749322. Its totient is φ = 689749320.

The previous prime is 689749303. The next prime is 689749327. The reversal of 689749321 is 123947986.

689749321 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., 638067600 + 51681721 = 25260^2 + 7189^2 .

It is a cyclic number.

It is not a de Polignac number, because 689749321 - 2⁵ = 689749289 is a prime.

It is a super-2 number, since 2×689749321² = 951508251639922082, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (689749327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344874660 + 344874661.

It is an arithmetic number, because the mean of its divisors is an integer number (344874661).

Almost surely, 2^689749321 is an apocalyptic number.

It is an amenable number.

689749321 is a deficient number, since it is larger than the sum of its proper divisors (1).

689749321 is an equidigital number, since it uses as much as digits as its factorization.

689749321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 653184, while the sum is 49.

The square root of 689749321 is about 26263.0790464485. The cubic root of 689749321 is about 883.5485677325.

The spelling of 689749321 in words is "six hundred eighty-nine million, seven hundred forty-nine thousand, three hundred twenty-one".