405391 has 8 divisors (see below), whose sum is σ = 479520. Its totient is φ = 335328.

The previous prime is 405373. The next prime is 405401. The reversal of 405391 is 193504.

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

It is a de Polignac number, because none of the positive numbers 2^k-405391 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405341) 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, 796 + ... + 1201.

It is an arithmetic number, because the mean of its divisors is an integer number (59940).

2⁴⁰⁵³⁹¹ is an apocalyptic number.

405391 is a deficient number, since it is larger than the sum of its proper divisors (74129).

405391 is a wasteful number, since it uses less digits than its factorization.

405391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2033.

The product of its (nonzero) digits is 540, while the sum is 22.

The square root of 405391 is about 636.7032275715. The cubic root of 405391 is about 74.0101641748.

Adding to 405391 its reverse (193504), we get a palindrome (598895).

The spelling of 405391 in words is "four hundred five thousand, three hundred ninety-one".