981561 has 16 divisors (see below), whose sum is σ = 1531904. Its totient is φ = 547344.

The previous prime is 981527. The next prime is 981569. The reversal of 981561 is 165189.

It is a happy number.

It is not a de Polignac number, because 981561 - 2⁹ = 981049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (981569) 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 15 ways as a sum of consecutive naturals, for example, 360 + ... + 1446.

It is an arithmetic number, because the mean of its divisors is an integer number (95744).

2⁹⁸¹⁵⁶¹ is an apocalyptic number.

It is an amenable number.

981561 is a deficient number, since it is larger than the sum of its proper divisors (550343).

981561 is a wasteful number, since it uses less digits than its factorization.

981561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1140.

The product of its digits is 2160, while the sum is 30.

The square root of 981561 is about 990.7376040103. The cubic root of 981561 is about 99.3815497443.

The spelling of 981561 in words is "nine hundred eighty-one thousand, five hundred sixty-one".