398976285821 has 2 divisors, whose sum is σ = 398976285822. Its totient is φ = 398976285820.

The previous prime is 398976285703. The next prime is 398976285863. The reversal of 398976285821 is 128582679893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 393442562500 + 5533723321 = 627250^2 + 74389^2 .

It is an emirp because it is prime and its reverse (128582679893) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 398976285821 - 2¹⁰ = 398976284797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (398976285871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199488142910 + 199488142911.

It is an arithmetic number, because the mean of its divisors is an integer number (199488142911).

Almost surely, 2^398976285821 is an apocalyptic number.

It is an amenable number.

398976285821 is a deficient number, since it is larger than the sum of its proper divisors (1).

398976285821 is an equidigital number, since it uses as much as digits as its factorization.

398976285821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 104509440, while the sum is 68.

The spelling of 398976285821 in words is "three hundred ninety-eight billion, nine hundred seventy-six million, two hundred eighty-five thousand, eight hundred twenty-one".