66606550650561 has 16 divisors (see below), whose sum is σ = 93377387980800. Its totient is φ = 42149515396560.

The previous prime is 66606550650551. The next prime is 66606550650613. The reversal of 66606550650561 is 16505605560666.

It is not a de Polignac number, because 66606550650561 - 2²¹ = 66606548553409 is a prime.

It is a super-2 number, since 2×66606550650561² (a number of 28 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66606550650551) 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, 3684389161 + ... + 3684407238.

It is an arithmetic number, because the mean of its divisors is an integer number (5836086748800).

Almost surely, 2^{66606550650561} is an apocalyptic number.

It is an amenable number.

66606550650561 is a deficient number, since it is larger than the sum of its proper divisors (26770837330239).

66606550650561 is a wasteful number, since it uses less digits than its factorization.

66606550650561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7368796556.

The product of its (nonzero) digits is 29160000, while the sum is 57.

The spelling of 66606550650561 in words is "sixty-six trillion, six hundred six billion, five hundred fifty million, six hundred fifty thousand, five hundred sixty-one".