661241 has 4 divisors (see below), whose sum is σ = 755712. Its totient is φ = 566772.

The previous prime is 661237. The next prime is 661253. The reversal of 661241 is 142166.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 661241 - 2² = 661237 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (661201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47225 + ... + 47238.

It is an arithmetic number, because the mean of its divisors is an integer number (188928).

2⁶⁶¹²⁴¹ is an apocalyptic number.

It is an amenable number.

661241 is a deficient number, since it is larger than the sum of its proper divisors (94471).

661241 is an equidigital number, since it uses as much as digits as its factorization.

661241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94470.

The product of its digits is 288, while the sum is 20.

The square root of 661241 is about 813.1672644665. The cubic root of 661241 is about 87.1204128221.

The spelling of 661241 in words is "six hundred sixty-one thousand, two hundred forty-one".