405405243 has 40 divisors (see below), whose sum is σ = 619423200. Its totient is φ = 264176640.

The previous prime is 405405233. The next prime is 405405257. The reversal of 405405243 is 342504504.

It is not a de Polignac number, because 405405243 - 2⁴ = 405405227 is a prime.

It is a super-2 number, since 2×405405243² = 328706822103778098, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (405405233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 902683 + ... + 903131.

It is an arithmetic number, because the mean of its divisors is an integer number (15485580).

Almost surely, 2^405405243 is an apocalyptic number.

405405243 is a deficient number, since it is larger than the sum of its proper divisors (214017957).

405405243 is a wasteful number, since it uses less digits than its factorization.

405405243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 689 (or 680 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 27.

The square root of 405405243 is about 20134.6776234436. The cubic root of 405405243 is about 740.1103092193.

Adding to 405405243 its reverse (342504504), we get a palindrome (747909747).

The spelling of 405405243 in words is "four hundred five million, four hundred five thousand, two hundred forty-three".