6661345545 has 24 divisors (see below), whose sum is σ = 11764191816. Its totient is φ = 3485683968.

The previous prime is 6661345529. The next prime is 6661345547. The reversal of 6661345545 is 5455431666.

6661345545 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 1359175689 + 5302169856 = 36867^2 + 72816^2 .

It is not a de Polignac number, because 6661345545 - 2⁴ = 6661345529 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 6661345545.

It is not an unprimeable number, because it can be changed into a prime (6661345547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1394124 + ... + 1398893.

It is an arithmetic number, because the mean of its divisors is an integer number (490174659).

Almost surely, 2^6661345545 is an apocalyptic number.

It is an amenable number.

6661345545 is a deficient number, since it is larger than the sum of its proper divisors (5102846271).

6661345545 is a wasteful number, since it uses less digits than its factorization.

6661345545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2793081 (or 2793078 counting only the distinct ones).

The product of its digits is 1296000, while the sum is 45.

The square root of 6661345545 is about 81617.0665057254. The cubic root of 6661345545 is about 1881.5711877587.

The spelling of 6661345545 in words is "six billion, six hundred sixty-one million, three hundred forty-five thousand, five hundred forty-five".