6616556364561 has 64 divisors (see below), whose sum is σ = 10620037908480. Its totient is φ = 3610506493440.

The previous prime is 6616556364553. The next prime is 6616556364601. The reversal of 6616556364561 is 1654636556166.

It is not a de Polignac number, because 6616556364561 - 2³ = 6616556364553 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 6616556364495 and 6616556364504.

It is not an unprimeable number, because it can be changed into a prime (6616556364541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 13164285 + ... + 13657653.

It is an arithmetic number, because the mean of its divisors is an integer number (165938092320).

Almost surely, 2^{6616556364561} is an apocalyptic number.

It is an amenable number.

6616556364561 is a deficient number, since it is larger than the sum of its proper divisors (4003481543919).

6616556364561 is a wasteful number, since it uses less digits than its factorization.

6616556364561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 494166.

The product of its digits is 69984000, while the sum is 60.

The spelling of 6616556364561 in words is "six trillion, six hundred sixteen billion, five hundred fifty-six million, three hundred sixty-four thousand, five hundred sixty-one".