308405 has 4 divisors (see below), whose sum is σ = 370092. Its totient is φ = 246720.

The previous prime is 308383. The next prime is 308411. The reversal of 308405 is 504803.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 178084 + 130321 = 422^2 + 361^2 .

It is not a de Polignac number, because 308405 - 2⁸ = 308149 is a prime.

It is a super-2 number, since 2×308405² = 190227288050, which contains 22 as substring.

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 308405.

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, 30836 + ... + 30845.

It is an arithmetic number, because the mean of its divisors is an integer number (92523).

2³⁰⁸⁴⁰⁵ is an apocalyptic number.

It is an amenable number.

308405 is a deficient number, since it is larger than the sum of its proper divisors (61687).

308405 is an equidigital number, since it uses as much as digits as its factorization.

308405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61686.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 308405 is about 555.3422368234. The cubic root of 308405 is about 67.5627217642.

The spelling of 308405 in words is "three hundred eight thousand, four hundred five".