6664955016621 has 16 divisors (see below), whose sum is σ = 9707021432640. Its totient is φ = 4034141089920.

The previous prime is 6664955016619. The next prime is 6664955016623. The reversal of 6664955016621 is 1266105594666.

It is an interprime number because it is at equal distance from previous prime (6664955016619) and next prime (6664955016623).

It is not a de Polignac number, because 6664955016621 - 2¹ = 6664955016619 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6664955016623) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 130613776 + ... + 130664793.

It is an arithmetic number, because the mean of its divisors is an integer number (606688839540).

Almost surely, 2^{6664955016621} is an apocalyptic number.

It is an amenable number.

6664955016621 is a deficient number, since it is larger than the sum of its proper divisors (3042066416019).

6664955016621 is a wasteful number, since it uses less digits than its factorization.

6664955016621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261279356.

The product of its (nonzero) digits is 13996800, while the sum is 57.

The spelling of 6664955016621 in words is "six trillion, six hundred sixty-four billion, nine hundred fifty-five million, sixteen thousand, six hundred twenty-one".