6660615005221 has 8 divisors (see below), whose sum is σ = 6705582312600. Its totient is φ = 6615651234048.

The previous prime is 6660615005189. The next prime is 6660615005249. The reversal of 6660615005221 is 1225005160666.

It can be written as a sum of positive squares in 4 ways, for example, as 12540640225 + 6648074364996 = 111985^2 + 2578386^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6660615005221 - 2⁵ = 6660615005189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6660615005021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2951745 + ... + 4694041.

It is an arithmetic number, because the mean of its divisors is an integer number (838197789075).

Almost surely, 2^{6660615005221} is an apocalyptic number.

It is an amenable number.

6660615005221 is a deficient number, since it is larger than the sum of its proper divisors (44967307379).

6660615005221 is a wasteful number, since it uses less digits than its factorization.

6660615005221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1768103.

The product of its (nonzero) digits is 129600, while the sum is 40.

The spelling of 6660615005221 in words is "six trillion, six hundred sixty billion, six hundred fifteen million, five thousand, two hundred twenty-one".