66584991906 has 48 divisors (see below), whose sum is σ = 147027980736. Its totient is φ = 21770525088.

The previous prime is 66584991901. The next prime is 66584991937. The reversal of 66584991906 is 60919948566.

66584991906 is a `hidden beast` number, since 6 + 6 + 58 + 499 + 1 + 90 + 6 = 666.

It is a super-2 number, since 2×66584991906² (a number of 22 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66584991901) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5186211 + ... + 5199033.

It is an arithmetic number, because the mean of its divisors is an integer number (3063082932).

Almost surely, 2^66584991906 is an apocalyptic number.

66584991906 is an abundant number, since it is smaller than the sum of its proper divisors (80442988830).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66584991906 is a wasteful number, since it uses less digits than its factorization.

66584991906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18327 (or 18324 counting only the distinct ones).

The product of its (nonzero) digits is 25194240, while the sum is 63.

The spelling of 66584991906 in words is "sixty-six billion, five hundred eighty-four million, nine hundred ninety-one thousand, nine hundred six".