66606774651 has 12 divisors (see below), whose sum is σ = 96217578600. Its totient is φ = 44400919680.

The previous prime is 66606774649. The next prime is 66606774659. The reversal of 66606774651 is 15647760666.

It is a happy number.

It is not a de Polignac number, because 66606774651 - 2¹ = 66606774649 is a prime.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (66606774659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 179926 + ... + 406923.

It is an arithmetic number, because the mean of its divisors is an integer number (8018131550).

Almost surely, 2^66606774651 is an apocalyptic number.

66606774651 is a deficient number, since it is larger than the sum of its proper divisors (29610803949).

66606774651 is a wasteful number, since it uses less digits than its factorization.

66606774651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 599466 (or 599463 counting only the distinct ones).

The product of its (nonzero) digits is 7620480, while the sum is 54.

The spelling of 66606774651 in words is "sixty-six billion, six hundred six million, seven hundred seventy-four thousand, six hundred fifty-one".