3998305 has 4 divisors (see below), whose sum is σ = 4797972. Its totient is φ = 3198640.

The previous prime is 3998299. The next prime is 3998333. The reversal of 3998305 is 5038993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5038993 = 37 ⋅136189.

It can be written as a sum of positive squares in 2 ways, for example, as 1347921 + 2650384 = 1161^2 + 1628^2 .

It is not a de Polignac number, because 3998305 - 2⁵ = 3998273 is a prime.

It is a Duffinian number.

3998305 is a lucky number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 399826 + ... + 399835.

It is an arithmetic number, because the mean of its divisors is an integer number (1199493).

Almost surely, 2^3998305 is an apocalyptic number.

It is an amenable number.

3998305 is a deficient number, since it is larger than the sum of its proper divisors (799667).

3998305 is an equidigital number, since it uses as much as digits as its factorization.

3998305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 799666.

The product of its (nonzero) digits is 29160, while the sum is 37.

The square root of 3998305 is about 1999.5762050995. The cubic root of 3998305 is about 158.7176799891.

The spelling of 3998305 in words is "three million, nine hundred ninety-eight thousand, three hundred five".