9725561 has 4 divisors (see below), whose sum is σ = 9988452. Its totient is φ = 9462672.

The previous prime is 9725539. The next prime is 9725563. The reversal of 9725561 is 1655279.

9725561 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.

It can be written as a sum of positive squares in 2 ways, for example, as 3400336 + 6325225 = 1844^2 + 2515^2 .

It is a cyclic number.

It is not a de Polignac number, because 9725561 - 2¹⁴ = 9709177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9725563) 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, 131390 + ... + 131463.

It is an arithmetic number, because the mean of its divisors is an integer number (2497113).

Almost surely, 2^9725561 is an apocalyptic number.

It is an amenable number.

9725561 is a deficient number, since it is larger than the sum of its proper divisors (262891).

9725561 is a wasteful number, since it uses less digits than its factorization.

9725561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262890.

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

The square root of 9725561 is about 3118.5831718907. The cubic root of 9725561 is about 213.4542898593.

The spelling of 9725561 in words is "nine million, seven hundred twenty-five thousand, five hundred sixty-one".