666355653 has 20 divisors (see below), whose sum is σ = 996143148. Its totient is φ = 443914560.

The previous prime is 666355637. The next prime is 666355673. The reversal of 666355653 is 356553666.

It can be written as a sum of positive squares in 2 ways, for example, as 316590849 + 349764804 = 17793^2 + 18702^2 .

It is not a de Polignac number, because 666355653 - 2⁴ = 666355637 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 666355599 and 666355608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666355673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 172483 + ... + 176303.

Almost surely, 2^666355653 is an apocalyptic number.

It is an amenable number.

666355653 is a deficient number, since it is larger than the sum of its proper divisors (329787495).

666355653 is a wasteful number, since it uses less digits than its factorization.

666355653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5986 (or 5977 counting only the distinct ones).

The product of its digits is 1458000, while the sum is 45.

The square root of 666355653 is about 25813.8655183605. The cubic root of 666355653 is about 873.4445958738. Note that the first 3 decimals are identical.

The spelling of 666355653 in words is "six hundred sixty-six million, three hundred fifty-five thousand, six hundred fifty-three".