66556100056601 has 4 divisors (see below), whose sum is σ = 66841748554932. Its totient is φ = 66270451558272.

The previous prime is 66556100056573. The next prime is 66556100056603. The reversal of 66556100056601 is 10665000165566.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3679510422025 + 62876589634576 = 1918205^2 + 7929476^2 .

It is a cyclic number.

It is not a de Polignac number, because 66556100056601 - 2¹⁴ = 66556100040217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66556100056603) 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, 142824248816 + ... + 142824249281.

It is an arithmetic number, because the mean of its divisors is an integer number (16710437138733).

Almost surely, 2^{66556100056601} is an apocalyptic number.

It is an amenable number.

66556100056601 is a deficient number, since it is larger than the sum of its proper divisors (285648498331).

66556100056601 is a wasteful number, since it uses less digits than its factorization.

66556100056601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285648498330.

The product of its (nonzero) digits is 972000, while the sum is 47.

The spelling of 66556100056601 in words is "sixty-six trillion, five hundred fifty-six billion, one hundred million, fifty-six thousand, six hundred one".