6566861326401 has 16 divisors (see below), whose sum is σ = 9728983422720. Its totient is φ = 4377772561680.

The previous prime is 6566861326393. The next prime is 6566861326483. The reversal of 6566861326401 is 1046231686656.

6566861326401 is a `hidden beast` number, since 6 + 566 + 8 + 6 + 1 + 32 + 6 + 40 + 1 = 666.

It is not a de Polignac number, because 6566861326401 - 2³ = 6566861326393 is a prime.

It is a super-2 number, since 2×6566861326401² (a number of 26 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6566861326301) 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, 2853945 + ... + 4612886.

It is an arithmetic number, because the mean of its divisors is an integer number (608061463920).

Almost surely, 2^{6566861326401} is an apocalyptic number.

It is an amenable number.

6566861326401 is a deficient number, since it is larger than the sum of its proper divisors (3162122096319).

6566861326401 is a wasteful number, since it uses less digits than its factorization.

6566861326401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7499413 (or 7499407 counting only the distinct ones).

The product of its (nonzero) digits is 7464960, while the sum is 54.

The spelling of 6566861326401 in words is "six trillion, five hundred sixty-six billion, eight hundred sixty-one million, three hundred twenty-six thousand, four hundred one".