3998609 has 2 divisors, whose sum is σ = 3998610. Its totient is φ = 3998608.

The previous prime is 3998591. The next prime is 3998623. The reversal of 3998609 is 9068993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2235025 + 1763584 = 1495^2 + 1328^2 .

It is an emirp because it is prime and its reverse (9068993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3998609 - 2⁸ = 3998353 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 3998609.

It is not a weakly prime, because it can be changed into another prime (3998629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1999304 + 1999305.

It is an arithmetic number, because the mean of its divisors is an integer number (1999305).

Almost surely, 2^3998609 is an apocalyptic number.

It is an amenable number.

3998609 is a deficient number, since it is larger than the sum of its proper divisors (1).

3998609 is an equidigital number, since it uses as much as digits as its factorization.

3998609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 104976, while the sum is 44.

The square root of 3998609 is about 1999.6522197622. The cubic root of 3998609 is about 158.7217024396.

The spelling of 3998609 in words is "three million, nine hundred ninety-eight thousand, six hundred nine".