660540161 has 2 divisors, whose sum is σ = 660540162. Its totient is φ = 660540160.

The previous prime is 660540143. The next prime is 660540227. The reversal of 660540161 is 161045066.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 637259536 + 23280625 = 25244^2 + 4825^2 .

It is a cyclic number.

It is not a de Polignac number, because 660540161 - 2¹⁴ = 660523777 is a prime.

It is not a weakly prime, because it can be changed into another prime (660540061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330270080 + 330270081.

It is an arithmetic number, because the mean of its divisors is an integer number (330270081).

Almost surely, 2^660540161 is an apocalyptic number.

It is an amenable number.

660540161 is a deficient number, since it is larger than the sum of its proper divisors (1).

660540161 is an equidigital number, since it uses as much as digits as its factorization.

660540161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 660540161 is about 25700.9758764137. The cubic root of 660540161 is about 870.8962275360.

The spelling of 660540161 in words is "six hundred sixty million, five hundred forty thousand, one hundred sixty-one".