501987409 has 24 divisors (see below), whose sum is σ = 645148800. Its totient is φ = 386174880.

The previous prime is 501987389. The next prime is 501987413. The reversal of 501987409 is 904789105.

It is not a de Polignac number, because 501987409 - 2¹⁵ = 501954641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (501987469) 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 23 ways as a sum of consecutive naturals, for example, 36687 + ... + 48475.

It is an arithmetic number, because the mean of its divisors is an integer number (26881200).

Almost surely, 2^501987409 is an apocalyptic number.

It is an amenable number.

501987409 is a deficient number, since it is larger than the sum of its proper divisors (143161391).

501987409 is a wasteful number, since it uses less digits than its factorization.

501987409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11893 (or 11886 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 43.

The square root of 501987409 is about 22405.0755187301. The cubic root of 501987409 is about 794.7507407856.

The spelling of 501987409 in words is "five hundred one million, nine hundred eighty-seven thousand, four hundred nine".