398785 has 4 divisors (see below), whose sum is σ = 478548. Its totient is φ = 319024.

The previous prime is 398771. The next prime is 398813. The reversal of 398785 is 587893.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 587893 = 37 ⋅15889.

It can be written as a sum of positive squares in 2 ways, for example, as 204304 + 194481 = 452^2 + 441^2 .

It is a cyclic number.

It is not a de Polignac number, because 398785 - 2⁹ = 398273 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian 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, 39874 + ... + 39883.

It is an arithmetic number, because the mean of its divisors is an integer number (119637).

2³⁹⁸⁷⁸⁵ is an apocalyptic number.

It is an amenable number.

398785 is a deficient number, since it is larger than the sum of its proper divisors (79763).

398785 is an equidigital number, since it uses as much as digits as its factorization.

398785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79762.

The product of its digits is 60480, while the sum is 40.

The square root of 398785 is about 631.4942596730. The cubic root of 398785 is about 73.6059526731.

The spelling of 398785 in words is "three hundred ninety-eight thousand, seven hundred eighty-five".