66120123511 has 16 divisors (see below), whose sum is σ = 74869270560. Its totient is φ = 57963265920.

The previous prime is 66120123491. The next prime is 66120123521. The reversal of 66120123511 is 11532102166.

It is a cyclic number.

It is not a de Polignac number, because 66120123511 - 2¹⁷ = 66119992439 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 66120123511.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66120123521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1414585 + ... + 1460578.

It is an arithmetic number, because the mean of its divisors is an integer number (4679329410).

Almost surely, 2^66120123511 is an apocalyptic number.

66120123511 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

66120123511 is a deficient number, since it is larger than the sum of its proper divisors (8749147049).

66120123511 is a wasteful number, since it uses less digits than its factorization.

66120123511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2875266.

The product of its (nonzero) digits is 2160, while the sum is 28.

Adding to 66120123511 its reverse (11532102166), we get a palindrome (77652225677).

The spelling of 66120123511 in words is "sixty-six billion, one hundred twenty million, one hundred twenty-three thousand, five hundred eleven".