285138405 has 12 divisors (see below), whose sum is σ = 494239980. Its totient is φ = 152073792.

The previous prime is 285138397. The next prime is 285138407. The reversal of 285138405 is 504831582.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 179747649 + 105390756 = 13407^2 + 10266^2 .

It is not a de Polignac number, because 285138405 - 2³ = 285138397 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 285138405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (285138407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3168160 + ... + 3168249.

It is an arithmetic number, because the mean of its divisors is an integer number (41186665).

Almost surely, 2^285138405 is an apocalyptic number.

It is an amenable number.

285138405 is a deficient number, since it is larger than the sum of its proper divisors (209101575).

285138405 is a wasteful number, since it uses less digits than its factorization.

285138405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6336420 (or 6336417 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 36.

The square root of 285138405 is about 16886.0417209007. The cubic root of 285138405 is about 658.1909481455.

Adding to 285138405 its reverse (504831582), we get a palindrome (789969987).

The spelling of 285138405 in words is "two hundred eighty-five million, one hundred thirty-eight thousand, four hundred five".