689309389 has 2 divisors, whose sum is σ = 689309390. Its totient is φ = 689309388.

The previous prime is 689309321. The next prime is 689309399. The reversal of 689309389 is 983903986.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 402684489 + 286624900 = 20067^2 + 16930^2 .

It is a cyclic number.

It is not a de Polignac number, because 689309389 - 2¹⁹ = 688785101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (689309399) 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 as a sum of consecutive naturals, namely, 344654694 + 344654695.

It is an arithmetic number, because the mean of its divisors is an integer number (344654695).

Almost surely, 2^689309389 is an apocalyptic number.

It is an amenable number.

689309389 is a deficient number, since it is larger than the sum of its proper divisors (1).

689309389 is an equidigital number, since it uses as much as digits as its factorization.

689309389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2519424, while the sum is 55.

The square root of 689309389 is about 26254.7022264584. The cubic root of 689309389 is about 883.3606811358.

It can be divided in two parts, 689 and 309389, that added together give a triangular number (310078 = T₇₈₇).

The spelling of 689309389 in words is "six hundred eighty-nine million, three hundred nine thousand, three hundred eighty-nine".