66442690406785 has 16 divisors (see below), whose sum is σ = 99405167985792. Its totient is φ = 41418819993600.

The previous prime is 66442690406779. The next prime is 66442690406821. The reversal of 66442690406785 is 58760409624466.

It is not a de Polignac number, because 66442690406785 - 2¹⁵ = 66442690374017 is a prime.

It is a super-2 number, since 2×66442690406785² (a number of 28 digits) contains 22 as substring.

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 66442690406785.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 86289207936 + ... + 86289208705.

It is an arithmetic number, because the mean of its divisors is an integer number (6212822999112).

Almost surely, 2^{66442690406785} is an apocalyptic number.

It is an amenable number.

66442690406785 is a deficient number, since it is larger than the sum of its proper divisors (32962477579007).

66442690406785 is a wasteful number, since it uses less digits than its factorization.

66442690406785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172578416664.

The product of its (nonzero) digits is 418037760, while the sum is 67.

The spelling of 66442690406785 in words is "sixty-six trillion, four hundred forty-two billion, six hundred ninety million, four hundred six thousand, seven hundred eighty-five".