66556600621601 has 8 divisors (see below), whose sum is σ = 66639286316064. Its totient is φ = 66473958670560.

The previous prime is 66556600621523. The next prime is 66556600621603. The reversal of 66556600621601 is 10612600665566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66556600621601 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66556600621601.

It is not an unprimeable number, because it can be changed into a prime (66556600621603) 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 7 ways as a sum of consecutive naturals, for example, 7890395 + ... + 13977536.

It is an arithmetic number, because the mean of its divisors is an integer number (8329910789508).

Almost surely, 2^{66556600621601} is an apocalyptic number.

It is an amenable number.

66556600621601 is a deficient number, since it is larger than the sum of its proper divisors (82685694463).

66556600621601 is a wasteful number, since it uses less digits than its factorization.

66556600621601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21871711.

The product of its (nonzero) digits is 2332800, while the sum is 50.

The spelling of 66556600621601 in words is "sixty-six trillion, five hundred fifty-six billion, six hundred million, six hundred twenty-one thousand, six hundred one".