660641 has 8 divisors (see below), whose sum is σ = 691968. Its totient is φ = 630000.

The previous prime is 660619. The next prime is 660643. The reversal of 660641 is 146066.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 660641 - 2¹⁴ = 644257 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3026 + ... + 3236.

It is an arithmetic number, because the mean of its divisors is an integer number (86496).

2⁶⁶⁰⁶⁴¹ is an apocalyptic number.

It is an amenable number.

660641 is a deficient number, since it is larger than the sum of its proper divisors (31327).

660641 is a wasteful number, since it uses less digits than its factorization.

660641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 660641 is about 812.7982529509. The cubic root of 660641 is about 87.0940542700.

The spelling of 660641 in words is "six hundred sixty thousand, six hundred forty-one".