660354561 has 12 divisors (see below), whose sum is σ = 957560292. Its totient is φ = 438521856.

The previous prime is 660354553. The next prime is 660354571. The reversal of 660354561 is 165453066.

660354561 is a `hidden beast` number, since 6 + 60 + 35 + 4 + 561 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 472801536 + 187553025 = 21744^2 + 13695^2 .

It is not a de Polignac number, because 660354561 - 2³ = 660354553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (660354521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 140436 + ... + 145061.

It is an arithmetic number, because the mean of its divisors is an integer number (79796691).

Almost surely, 2^660354561 is an apocalyptic number.

It is an amenable number.

660354561 is a deficient number, since it is larger than the sum of its proper divisors (297205731).

660354561 is a wasteful number, since it uses less digits than its factorization.

660354561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285760 (or 285757 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The square root of 660354561 is about 25697.3648649039. The cubic root of 660354561 is about 870.8146511278.

The spelling of 660354561 in words is "six hundred sixty million, three hundred fifty-four thousand, five hundred sixty-one".