66016512817811 has 4 divisors (see below), whose sum is σ = 67001833904712. Its totient is φ = 65031191730912.

The previous prime is 66016512817771. The next prime is 66016512817861. The reversal of 66016512817811 is 11871821561066.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 66016512817811 - 2³⁸ = 65741634910867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66016512817861) 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, 492660543350 + ... + 492660543483.

It is an arithmetic number, because the mean of its divisors is an integer number (16750458476178).

Almost surely, 2^{66016512817811} is an apocalyptic number.

66016512817811 is a deficient number, since it is larger than the sum of its proper divisors (985321086901).

66016512817811 is an equidigital number, since it uses as much as digits as its factorization.

66016512817811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 985321086900.

The product of its (nonzero) digits is 967680, while the sum is 53.

The spelling of 66016512817811 in words is "sixty-six trillion, sixteen billion, five hundred twelve million, eight hundred seventeen thousand, eight hundred eleven".