290405 has 6 divisors (see below), whose sum is σ = 349938. Its totient is φ = 231360.

The previous prime is 290399. The next prime is 290419. The reversal of 290405 is 504092.

It can be written as a sum of positive squares in 3 ways, for example, as 88804 + 201601 = 298^2 + 449^2 .

It is not a de Polignac number, because 290405 - 2¹⁰ = 289381 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 290405.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1085 + ... + 1325.

It is an arithmetic number, because the mean of its divisors is an integer number (58323).

2²⁹⁰⁴⁰⁵ is an apocalyptic number.

It is an amenable number.

290405 is a deficient number, since it is larger than the sum of its proper divisors (59533).

290405 is an frugal number, since it uses more digits than its factorization.

290405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 487 (or 246 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 290405 is about 538.8923825774. The cubic root of 290405 is about 66.2218582268.

Multiplying 290405 by its sum of digits (20), we get a square (5808100 = 2410²).

Adding to 290405 its reverse (504092), we get a palindrome (794497).

The spelling of 290405 in words is "two hundred ninety thousand, four hundred five".