398823869 has 2 divisors, whose sum is σ = 398823870. Its totient is φ = 398823868.

The previous prime is 398823857. The next prime is 398823877. The reversal of 398823869 is 968328893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 398521369 + 302500 = 19963^2 + 550^2 .

It is a cyclic number.

It is not a de Polignac number, because 398823869 - 2²⁰ = 397775293 is a prime.

It is a super-2 number, since 2×398823869² = 318120956968258322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (398823899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199411934 + 199411935.

It is an arithmetic number, because the mean of its divisors is an integer number (199411935).

Almost surely, 2^398823869 is an apocalyptic number.

It is an amenable number.

398823869 is a deficient number, since it is larger than the sum of its proper divisors (1).

398823869 is an equidigital number, since it uses as much as digits as its factorization.

398823869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4478976, while the sum is 56.

The square root of 398823869 is about 19970.5750793511. The cubic root of 398823869 is about 736.0834401748.

The spelling of 398823869 in words is "three hundred ninety-eight million, eight hundred twenty-three thousand, eight hundred sixty-nine".