398708689 has 2 divisors, whose sum is σ = 398708690. Its totient is φ = 398708688.

The previous prime is 398708621. The next prime is 398708693. The reversal of 398708689 is 986807893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 336172225 + 62536464 = 18335^2 + 7908^2 .

It is a cyclic number.

It is not a de Polignac number, because 398708689 - 2⁷ = 398708561 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (398708389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199354344 + 199354345.

It is an arithmetic number, because the mean of its divisors is an integer number (199354345).

Almost surely, 2^398708689 is an apocalyptic number.

It is an amenable number.

398708689 is a deficient number, since it is larger than the sum of its proper divisors (1).

398708689 is an equidigital number, since it uses as much as digits as its factorization.

398708689 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5225472, while the sum is 58.

The square root of 398708689 is about 19967.6911284204. The cubic root of 398708689 is about 736.0125732582.

The spelling of 398708689 in words is "three hundred ninety-eight million, seven hundred eight thousand, six hundred eighty-nine".