3998521 has 2 divisors, whose sum is σ = 3998522. Its totient is φ = 3998520.

The previous prime is 3998497. The next prime is 3998537. The reversal of 3998521 is 1258993.

3998521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3980025 + 18496 = 1995^2 + 136^2 .

It is an emirp because it is prime and its reverse (1258993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3998521 - 2²¹ = 1901369 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (3998551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1999260 + 1999261.

It is an arithmetic number, because the mean of its divisors is an integer number (1999261).

Almost surely, 2^3998521 is an apocalyptic number.

It is an amenable number.

3998521 is a deficient number, since it is larger than the sum of its proper divisors (1).

3998521 is an equidigital number, since it uses as much as digits as its factorization.

3998521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19440, while the sum is 37.

The square root of 3998521 is about 1999.6302158149. The cubic root of 3998521 is about 158.7205380670.

The spelling of 3998521 in words is "three million, nine hundred ninety-eight thousand, five hundred twenty-one".