6661065613 has 4 divisors (see below), whose sum is σ = 7052893020. Its totient is φ = 6269238208.

The previous prime is 6661065611. The next prime is 6661065641. The reversal of 6661065613 is 3165601666.

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 5340978724 + 1320086889 = 73082^2 + 36333^2 .

It is a cyclic number.

It is not a de Polignac number, because 6661065613 - 2¹ = 6661065611 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6661065611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 195913678 + ... + 195913711.

It is an arithmetic number, because the mean of its divisors is an integer number (1763223255).

Almost surely, 2^6661065613 is an apocalyptic number.

It is an amenable number.

6661065613 is a deficient number, since it is larger than the sum of its proper divisors (391827407).

6661065613 is a wasteful number, since it uses less digits than its factorization.

6661065613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391827406.

The product of its (nonzero) digits is 116640, while the sum is 40.

The square root of 6661065613 is about 81615.3515767714. The cubic root of 6661065613 is about 1881.5448307531.

The spelling of 6661065613 in words is "six billion, six hundred sixty-one million, sixty-five thousand, six hundred thirteen".