9721601 has 4 divisors (see below), whose sum is σ = 9810900. Its totient is φ = 9632304.

The previous prime is 9721589. The next prime is 9721609. The reversal of 9721601 is 1061279.

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 3591025 + 6130576 = 1895^2 + 2476^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9721601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9721609) 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, 44486 + ... + 44703.

It is an arithmetic number, because the mean of its divisors is an integer number (2452725).

Almost surely, 2^9721601 is an apocalyptic number.

It is an amenable number.

9721601 is a deficient number, since it is larger than the sum of its proper divisors (89299).

9721601 is a wasteful number, since it uses less digits than its factorization.

9721601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89298.

The product of its (nonzero) digits is 756, while the sum is 26.

The square root of 9721601 is about 3117.9482035467. The cubic root of 9721601 is about 213.4253148817.

The spelling of 9721601 in words is "nine million, seven hundred twenty-one thousand, six hundred one".