398405 has 8 divisors (see below), whose sum is σ = 546432. Its totient is φ = 273168.

The previous prime is 398393. The next prime is 398407. The reversal of 398405 is 504893.

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

It is not a de Polignac number, because 398405 - 2⁶ = 398341 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 398405.

It is not an unprimeable number, because it can be changed into a prime (398407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5657 + ... + 5726.

It is an arithmetic number, because the mean of its divisors is an integer number (68304).

2³⁹⁸⁴⁰⁵ is an apocalyptic number.

398405 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

398405 is a deficient number, since it is larger than the sum of its proper divisors (148027).

398405 is a wasteful number, since it uses less digits than its factorization.

398405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11395.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 398405 is about 631.1933142865. The cubic root of 398405 is about 73.5825656759.

The spelling of 398405 in words is "three hundred ninety-eight thousand, four hundred five".