9987409 has 4 divisors (see below), whose sum is σ = 9993780. Its totient is φ = 9981040.

The previous prime is 9987403. The next prime is 9987413. The reversal of 9987409 is 9047899.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 7728400 + 2259009 = 2780^2 + 1503^2 .

It is a cyclic number.

It is not a de Polignac number, because 9987409 - 2⁹ = 9986897 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (9987403) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 999 + ... + 4579.

It is an arithmetic number, because the mean of its divisors is an integer number (2498445).

Almost surely, 2^9987409 is an apocalyptic number.

It is an amenable number.

9987409 is a deficient number, since it is larger than the sum of its proper divisors (6371).

9987409 is a wasteful number, since it uses less digits than its factorization.

9987409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6370.

The product of its (nonzero) digits is 163296, while the sum is 46.

The square root of 9987409 is about 3160.2862212148. The cubic root of 9987409 is about 215.3530094027.

The spelling of 9987409 in words is "nine million, nine hundred eighty-seven thousand, four hundred nine".