1009561 has 4 divisors (see below), whose sum is σ = 1153792. Its totient is φ = 865332.

The previous prime is 1009559. The next prime is 1009573. The reversal of 1009561 is 1659001.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1659001 = 127 ⋅13063.

It is a cyclic number.

It is not a de Polignac number, because 1009561 - 2¹ = 1009559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1009501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72105 + ... + 72118.

It is an arithmetic number, because the mean of its divisors is an integer number (288448).

2^1009561 is an apocalyptic number.

It is an amenable number.

1009561 is a deficient number, since it is larger than the sum of its proper divisors (144231).

1009561 is an equidigital number, since it uses as much as digits as its factorization.

1009561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144230.

The product of its (nonzero) digits is 270, while the sum is 22.

The square root of 1009561 is about 1004.7691277104. The cubic root of 1009561 is about 100.3176896640.

The spelling of 1009561 in words is "one million, nine thousand, five hundred sixty-one".