9721409 has 4 divisors (see below), whose sum is σ = 10056660. Its totient is φ = 9386160.

The previous prime is 9721373. The next prime is 9721421. The reversal of 9721409 is 9041279.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3330625 + 6390784 = 1825^2 + 2528^2 .

It is a cyclic number.

It is not a de Polignac number, because 9721409 - 2¹² = 9717313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9721429) 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, 167582 + ... + 167639.

It is an arithmetic number, because the mean of its divisors is an integer number (2514165).

Almost surely, 2^9721409 is an apocalyptic number.

It is an amenable number.

9721409 is a deficient number, since it is larger than the sum of its proper divisors (335251).

9721409 is a wasteful number, since it uses less digits than its factorization.

9721409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 335250.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 9721409 is about 3117.9174139159. The cubic root of 9721409 is about 213.4239098343.

The spelling of 9721409 in words is "nine million, seven hundred twenty-one thousand, four hundred nine".