3998504821 has 2 divisors, whose sum is σ = 3998504822. Its totient is φ = 3998504820.

The previous prime is 3998504819. The next prime is 3998504843. The reversal of 3998504821 is 1284058993.

3998504821 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2422017796 + 1576487025 = 49214^2 + 39705^2 .

It is a cyclic number.

It is not a de Polignac number, because 3998504821 - 2¹ = 3998504819 is a prime.

Together with 3998504819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3998508821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1999252410 + 1999252411.

It is an arithmetic number, because the mean of its divisors is an integer number (1999252411).

Almost surely, 2^3998504821 is an apocalyptic number.

It is an amenable number.

3998504821 is a deficient number, since it is larger than the sum of its proper divisors (1).

3998504821 is an equidigital number, since it uses as much as digits as its factorization.

3998504821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 622080, while the sum is 49.

The square root of 3998504821 is about 63233.7316706835. The cubic root of 3998504821 is about 1587.2032399260.

The spelling of 3998504821 in words is "three billion, nine hundred ninety-eight million, five hundred four thousand, eight hundred twenty-one".