6566557060221 has 4 divisors (see below), whose sum is σ = 8755409413632. Its totient is φ = 4377704706812.

The previous prime is 6566557060211. The next prime is 6566557060229. The reversal of 6566557060221 is 1220607556656.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6566557060221 - 2¹⁰ = 6566557059197 is a prime.

It is a super-3 number, since 3×6566557060221³ (a number of 39 digits) contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6566557060229) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1094426176701 + ... + 1094426176706.

It is an arithmetic number, because the mean of its divisors is an integer number (2188852353408).

Almost surely, 2^{6566557060221} is an apocalyptic number.

It is an amenable number.

6566557060221 is a deficient number, since it is larger than the sum of its proper divisors (2188852353411).

6566557060221 is a wasteful number, since it uses less digits than its factorization.

6566557060221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2188852353410.

The product of its (nonzero) digits is 4536000, while the sum is 51.

The spelling of 6566557060221 in words is "six trillion, five hundred sixty-six billion, five hundred fifty-seven million, sixty thousand, two hundred twenty-one".