661201 has 2 divisors, whose sum is σ = 661202. Its totient is φ = 661200.

The previous prime is 661189. The next prime is 661217. The reversal of 661201 is 102166.

It is an a-pointer prime, because the next prime (661217) can be obtained adding 661201 to its sum of digits (16).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 641601 + 19600 = 801^2 + 140^2 .

It is a cyclic number.

It is not a de Polignac number, because 661201 - 2¹⁷ = 530129 is a prime.

It is not a weakly prime, because it can be changed into another prime (661231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330600 + 330601.

It is an arithmetic number, because the mean of its divisors is an integer number (330601).

2⁶⁶¹²⁰¹ is an apocalyptic number.

It is an amenable number.

661201 is a deficient number, since it is larger than the sum of its proper divisors (1).

661201 is an equidigital number, since it uses as much as digits as its factorization.

661201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 661201 is about 813.1426689087. The cubic root of 661201 is about 87.1186560814.

Adding to 661201 its reverse (102166), we get a palindrome (763367).

The spelling of 661201 in words is "six hundred sixty-one thousand, two hundred one".