6652720645 has 4 divisors (see below), whose sum is σ = 7983264780. Its totient is φ = 5322176512.

The previous prime is 6652720603. The next prime is 6652720649. The reversal of 6652720645 is 5460272566.

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 3091137604 + 3561583041 = 55598^2 + 59679^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6652720645 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6652720649) 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 3 ways as a sum of consecutive naturals, for example, 665272060 + ... + 665272069.

It is an arithmetic number, because the mean of its divisors is an integer number (1995816195).

Almost surely, 2^6652720645 is an apocalyptic number.

It is an amenable number.

6652720645 is a deficient number, since it is larger than the sum of its proper divisors (1330544135).

6652720645 is a wasteful number, since it uses less digits than its factorization.

6652720645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1330544134.

The product of its (nonzero) digits is 604800, while the sum is 43.

The square root of 6652720645 is about 81564.2117904660. The cubic root of 6652720645 is about 1880.7587706946.

The spelling of 6652720645 in words is "six billion, six hundred fifty-two million, seven hundred twenty thousand, six hundred forty-five".