66191047 has 12 divisors (see below), whose sum is σ = 75893760. Its totient is φ = 57502848.

The previous prime is 66191029. The next prime is 66191053. The reversal of 66191047 is 74019166.

It is a de Polignac number, because none of the positive numbers 2^k-66191047 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66191017) 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, 8647 + ... + 14392.

It is an arithmetic number, because the mean of its divisors is an integer number (6324480).

Almost surely, 2^66191047 is an apocalyptic number.

66191047 is a deficient number, since it is larger than the sum of its proper divisors (9702713).

66191047 is a wasteful number, since it uses less digits than its factorization.

66191047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23082 (or 23069 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 34.

The square root of 66191047 is about 8135.7880380452. The cubic root of 66191047 is about 404.5135591446.

The spelling of 66191047 in words is "sixty-six million, one hundred ninety-one thousand, forty-seven".