688708213 has 2 divisors, whose sum is σ = 688708214. Its totient is φ = 688708212.

The previous prime is 688708151. The next prime is 688708217. The reversal of 688708213 is 312807886.

It is a happy number.

688708213 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., 417875364 + 270832849 = 20442^2 + 16457^2 .

It is a cyclic number.

It is not a de Polignac number, because 688708213 - 2²¹ = 686611061 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 688708213.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688708217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344354106 + 344354107.

It is an arithmetic number, because the mean of its divisors is an integer number (344354107).

Almost surely, 2^688708213 is an apocalyptic number.

It is an amenable number.

688708213 is a deficient number, since it is larger than the sum of its proper divisors (1).

688708213 is an equidigital number, since it uses as much as digits as its factorization.

688708213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 129024, while the sum is 43.

The square root of 688708213 is about 26243.2508085412. The cubic root of 688708213 is about 883.1038009843.

The spelling of 688708213 in words is "six hundred eighty-eight million, seven hundred eight thousand, two hundred thirteen".