66541947649 has 8 divisors (see below), whose sum is σ = 70337232000. Its totient is φ = 62775970992.

The previous prime is 66541947643. The next prime is 66541947673. The reversal of 66541947649 is 94674914566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66541947649 - 2²¹ = 66539850497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66541947643) 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 7 ways as a sum of consecutive naturals, for example, 7322254 + ... + 7331335.

It is an arithmetic number, because the mean of its divisors is an integer number (8792154000).

Almost surely, 2^66541947649 is an apocalyptic number.

It is an amenable number.

66541947649 is a deficient number, since it is larger than the sum of its proper divisors (3795284351).

66541947649 is a wasteful number, since it uses less digits than its factorization.

66541947649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14653847.

The product of its digits is 39191040, while the sum is 61.

The spelling of 66541947649 in words is "sixty-six billion, five hundred forty-one million, nine hundred forty-seven thousand, six hundred forty-nine".