206664645331345 has 4 divisors (see below), whose sum is σ = 247997574397620. Its totient is φ = 165331716265072.

The previous prime is 206664645331321. The next prime is 206664645331349. The reversal of 206664645331345 is 543133546466602.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 68038676085136 + 138625969246209 = 8248556^2 + 11773953^2 .

It is a cyclic number.

It is not a de Polignac number, because 206664645331345 - 2²¹ = 206664643234193 is a prime.

It is a super-3 number, since 3×206664645331345³ (a number of 44 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 206664645331345.

It is not an unprimeable number, because it can be changed into a prime (206664645331349) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20666464533130 + ... + 20666464533139.

It is an arithmetic number, because the mean of its divisors is an integer number (61999393599405).

Almost surely, 2^{206664645331345} is an apocalyptic number.

It is an amenable number.

206664645331345 is a deficient number, since it is larger than the sum of its proper divisors (41332929066275).

206664645331345 is an equidigital number, since it uses as much as digits as its factorization.

206664645331345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41332929066274.

The product of its (nonzero) digits is 111974400, while the sum is 58.

The spelling of 206664645331345 in words is "two hundred six trillion, six hundred sixty-four billion, six hundred forty-five million, three hundred thirty-one thousand, three hundred forty-five".