505940409 has 24 divisors (see below), whose sum is σ = 814162440. Its totient is φ = 300609792.

The previous prime is 505940389. The next prime is 505940447. The reversal of 505940409 is 904049505.

It can be written as a sum of positive squares in 4 ways, for example, as 42614784 + 463325625 = 6528^2 + 21525^2 .

It is not a de Polignac number, because 505940409 - 2⁹ = 505939897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (505940509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 71164 + ... + 77949.

It is an arithmetic number, because the mean of its divisors is an integer number (33923435).

Almost surely, 2^505940409 is an apocalyptic number.

It is an amenable number.

505940409 is a deficient number, since it is larger than the sum of its proper divisors (308222031).

505940409 is a wasteful number, since it uses less digits than its factorization.

505940409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149161 (or 149158 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 505940409 is about 22493.1191478639. The cubic root of 505940409 is about 796.8314297931.

The spelling of 505940409 in words is "five hundred five million, nine hundred forty thousand, four hundred nine".