399545 has 8 divisors (see below), whose sum is σ = 491400. Its totient is φ = 311680.

The previous prime is 399541. The next prime is 399557. The reversal of 399545 is 545993.

It can be written as a sum of positive squares in 4 ways, for example, as 16384 + 383161 = 128^2 + 619^2 .

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

It is not a de Polignac number, because 399545 - 2² = 399541 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (399541) 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, 770 + ... + 1179.

It is an arithmetic number, because the mean of its divisors is an integer number (61425).

2³⁹⁹⁵⁴⁵ is an apocalyptic number.

It is an amenable number.

399545 is a deficient number, since it is larger than the sum of its proper divisors (91855).

399545 is a wasteful number, since it uses less digits than its factorization.

399545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1995.

The product of its digits is 24300, while the sum is 35.

The square root of 399545 is about 632.0957205993. The cubic root of 399545 is about 73.6526821344.

The spelling of 399545 in words is "three hundred ninety-nine thousand, five hundred forty-five".