66104105831781 has 16 divisors (see below), whose sum is σ = 90564395035584. Its totient is φ = 42857753871744.

The previous prime is 66104105831767. The next prime is 66104105831807. The reversal of 66104105831781 is 18713850140166.

It is not a de Polignac number, because 66104105831781 - 2¹⁸ = 66104105569637 is a prime.

It is a super-2 number, since 2×66104105831781² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66104105831381) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 142719456 + ... + 143181881.

It is an arithmetic number, because the mean of its divisors is an integer number (5660274689724).

Almost surely, 2^{66104105831781} is an apocalyptic number.

It is an amenable number.

66104105831781 is a deficient number, since it is larger than the sum of its proper divisors (24460289203803).

66104105831781 is a wasteful number, since it uses less digits than its factorization.

66104105831781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285903460.

The product of its (nonzero) digits is 967680, while the sum is 51.

The spelling of 66104105831781 in words is "sixty-six trillion, one hundred four billion, one hundred five million, eight hundred thirty-one thousand, seven hundred eighty-one".