399445 has 4 divisors (see below), whose sum is σ = 479340. Its totient is φ = 319552.

The previous prime is 399439. The next prime is 399473. The reversal of 399445 is 544993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 544993 = 659 ⋅827.

It can be written as a sum of positive squares in 2 ways, for example, as 93636 + 305809 = 306^2 + 553^2 .

It is a cyclic number.

It is not a de Polignac number, because 399445 - 2⁹ = 398933 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 399445.

It is a congruent 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, 39940 + ... + 39949.

It is an arithmetic number, because the mean of its divisors is an integer number (119835).

2³⁹⁹⁴⁴⁵ is an apocalyptic number.

It is an amenable number.

399445 is a deficient number, since it is larger than the sum of its proper divisors (79895).

399445 is an equidigital number, since it uses as much as digits as its factorization.

399445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79894.

The product of its digits is 19440, while the sum is 34.

The square root of 399445 is about 632.0166137057. The cubic root of 399445 is about 73.6465369085.

The spelling of 399445 in words is "three hundred ninety-nine thousand, four hundred forty-five".