398581 has 2 divisors, whose sum is σ = 398582. Its totient is φ = 398580.

The previous prime is 398569. The next prime is 398591. The reversal of 398581 is 185893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 396900 + 1681 = 630^2 + 41^2 .

It is an emirp because it is prime and its reverse (185893) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 398581 - 2⁵ = 398549 is a prime.

It is a super-2 number, since 2×398581² = 317733627122, which contains 22 as substring.

It is a plaindrome in base 9.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (398591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199290 + 199291.

It is an arithmetic number, because the mean of its divisors is an integer number (199291).

2³⁹⁸⁵⁸¹ is an apocalyptic number.

398581 is the 365-th hex number.

It is an amenable number.

398581 is a deficient number, since it is larger than the sum of its proper divisors (1).

398581 is an equidigital number, since it uses as much as digits as its factorization.

398581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 34.

The square root of 398581 is about 631.3327173527. The cubic root of 398581 is about 73.5933993962.

It can be divided in two parts, 398 and 581, that added together give a palindrome (979).

The spelling of 398581 in words is "three hundred ninety-eight thousand, five hundred eighty-one".