661041 has 10 divisors (see below), whose sum is σ = 987602. Its totient is φ = 440640.

The previous prime is 661027. The next prime is 661049. The reversal of 661041 is 140166.

661041 is a `hidden beast` number, since 661 + 0 + 4 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 531441 + 129600 = 729^2 + 360^2 .

It is not a de Polignac number, because 661041 - 2⁵ = 661009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661049) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 4000 + ... + 4161.

2⁶⁶¹⁰⁴¹ is an apocalyptic number.

It is an amenable number.

661041 is a deficient number, since it is larger than the sum of its proper divisors (326561).

661041 is an equidigital number, since it uses as much as digits as its factorization.

661041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8173 (or 8164 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 661041 is about 813.0442792370. The cubic root of 661041 is about 87.1116284103. Note that the first 3 decimals are identical.

The spelling of 661041 in words is "six hundred sixty-one thousand, forty-one".