66116556001 has 4 divisors (see below), whose sum is σ = 66117122500. Its totient is φ = 66115989504.

The previous prime is 66116555977. The next prime is 66116556053. The reversal of 66116556001 is 10065561166.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 30476779776 + 35639776225 = 174576^2 + 188785^2 .

It is a cyclic number.

It is not a de Polignac number, because 66116556001 - 2⁵ = 66116555969 is a prime.

It is a super-2 number, since 2×66116556001² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66116556071) 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 3 ways as a sum of consecutive naturals, for example, 36576 + ... + 365473.

It is an arithmetic number, because the mean of its divisors is an integer number (16529280625).

Almost surely, 2^66116556001 is an apocalyptic number.

It is an amenable number.

66116556001 is a deficient number, since it is larger than the sum of its proper divisors (566499).

66116556001 is a wasteful number, since it uses less digits than its factorization.

66116556001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 566498.

The product of its (nonzero) digits is 32400, while the sum is 37.

The spelling of 66116556001 in words is "sixty-six billion, one hundred sixteen million, five hundred fifty-six thousand, one".