66000984561801 has 27 divisors (see below), whose sum is σ = 95457177398037. Its totient is φ = 43944226382880.

The previous prime is 66000984561769. The next prime is 66000984561881. The reversal of 66000984561801 is 10816548900066.

The square root of 66000984561801 is 8124099.

It is a perfect power (a square), and thus also a powerful number.

66000984561801 is a `hidden beast` number, since 6 + 6 + 0 + 0 + 0 + 9 + 8 + 456 + 180 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 4927134681225 + 61073849880576 = 2219715^2 + 7814976^2 .

It is not a de Polignac number, because 66000984561801 - 2⁵ = 66000984561769 is a prime.

It is a super-2 number, since 2×66000984561801² (a number of 28 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66000984561881) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 28783681611 + ... + 28783683903.

Almost surely, 2^{66000984561801} is an apocalyptic number.

66000984561801 is the 8124099-th square number.

66000984561801 is the 4062050-th centered octagonal number.

It is an amenable number.

66000984561801 is a deficient number, since it is larger than the sum of its proper divisors (29456192836236).

66000984561801 is an frugal number, since it uses more digits than its factorization.

66000984561801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6954 (or 3477 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 54.

The spelling of 66000984561801 in words is "sixty-six trillion, nine hundred eighty-four million, five hundred sixty-one thousand, eight hundred one".