398945 has 8 divisors (see below), whose sum is σ = 485736. Its totient is φ = 314496.

The previous prime is 398941. The next prime is 398969. The reversal of 398945 is 549893.

398945 is nontrivially palindromic in base 8.

It can be written as a sum of positive squares in 4 ways, for example, as 160801 + 238144 = 401^2 + 488^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 398945 - 2² = 398941 is a prime.

It is a super-2 number, since 2×398945² = 318314226050, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 398899 and 398908.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398941) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 182 + ... + 911.

It is an arithmetic number, because the mean of its divisors is an integer number (60717).

2³⁹⁸⁹⁴⁵ is an apocalyptic number.

398945 is the 365-th octagonal number.

It is an amenable number.

398945 is a deficient number, since it is larger than the sum of its proper divisors (86791).

398945 is a wasteful number, since it uses less digits than its factorization.

398945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1171.

The product of its digits is 38880, while the sum is 38.

The square root of 398945 is about 631.6209306222. The cubic root of 398945 is about 73.6157953851.

It can be divided in two parts, 3 and 98945, that multiplied together give a triangular number (296835 = T₇₇₀).

The spelling of 398945 in words is "three hundred ninety-eight thousand, nine hundred forty-five".