398986657 has 2 divisors, whose sum is σ = 398986658. Its totient is φ = 398986656.

The previous prime is 398986639. The next prime is 398986667. The reversal of 398986657 is 756689893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 382632721 + 16353936 = 19561^2 + 4044^2 .

It is a cyclic number.

It is not a de Polignac number, because 398986657 - 2¹⁹ = 398462369 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 398986595 and 398986604.

It is not a weakly prime, because it can be changed into another prime (398986667) 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, 199493328 + 199493329.

It is an arithmetic number, because the mean of its divisors is an integer number (199493329).

Almost surely, 2^398986657 is an apocalyptic number.

It is an amenable number.

398986657 is a deficient number, since it is larger than the sum of its proper divisors (1).

398986657 is an equidigital number, since it uses as much as digits as its factorization.

398986657 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19595520, while the sum is 61.

The square root of 398986657 is about 19974.6503598937. The cubic root of 398986657 is about 736.1835756489.

The spelling of 398986657 in words is "three hundred ninety-eight million, nine hundred eighty-six thousand, six hundred fifty-seven".