9556721 has 4 divisors (see below), whose sum is σ = 9651444. Its totient is φ = 9462000.

The previous prime is 9556699. The next prime is 9556739. The reversal of 9556721 is 1276559.

9556721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1276559 = 317 ⋅4027.

It can be written as a sum of positive squares in 2 ways, for example, as 5125696 + 4431025 = 2264^2 + 2105^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9556721 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9556751) 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, 47210 + ... + 47411.

It is an arithmetic number, because the mean of its divisors is an integer number (2412861).

Almost surely, 2^9556721 is an apocalyptic number.

It is an amenable number.

9556721 is a deficient number, since it is larger than the sum of its proper divisors (94723).

9556721 is a wasteful number, since it uses less digits than its factorization.

9556721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94722.

The product of its digits is 18900, while the sum is 35.

The square root of 9556721 is about 3091.3946690774. The cubic root of 9556721 is about 212.2118521269.

The spelling of 9556721 in words is "nine million, five hundred fifty-six thousand, seven hundred twenty-one".