66851594631 has 12 divisors (see below), whose sum is σ = 102243615552. Its totient is φ = 41946098496.

The previous prime is 66851594533. The next prime is 66851594647. The reversal of 66851594631 is 13649515866.

66851594631 is a `hidden beast` number, since 6 + 6 + 8 + 515 + 94 + 6 + 31 = 666.

It is not a de Polignac number, because 66851594631 - 2¹⁰ = 66851593607 is a prime.

It is a super-2 number, since 2×66851594631² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66851594651) 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 11 ways as a sum of consecutive naturals, for example, 218469111 + ... + 218469416.

It is an arithmetic number, because the mean of its divisors is an integer number (8520301296).

Almost surely, 2^66851594631 is an apocalyptic number.

66851594631 is a deficient number, since it is larger than the sum of its proper divisors (35392020921).

66851594631 is a wasteful number, since it uses less digits than its factorization.

66851594631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 436938550 (or 436938547 counting only the distinct ones).

The product of its digits is 4665600, while the sum is 54.

The spelling of 66851594631 in words is "sixty-six billion, eight hundred fifty-one million, five hundred ninety-four thousand, six hundred thirty-one".