66571993087 has 8 divisors (see below), whose sum is σ = 66893359104. Its totient is φ = 66251144568.

The previous prime is 66571993051. The next prime is 66571993121. The reversal of 66571993087 is 78039917566.

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 66571993087 - 2²³ = 66563604479 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 (66571996087) by changing a digit.

Being equal to 31×2³¹-1, it is a Woodall number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 129778 + ... + 387280.

It is an arithmetic number, because the mean of its divisors is an integer number (8361669888).

Almost surely, 2^66571993087 is an apocalyptic number.

66571993087 is a deficient number, since it is larger than the sum of its proper divisors (321366017).

66571993087 is a wasteful number, since it uses less digits than its factorization.

66571993087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258749.

The product of its (nonzero) digits is 17146080, while the sum is 61.

The spelling of 66571993087 in words is "sixty-six billion, five hundred seventy-one million, nine hundred ninety-three thousand, eighty-seven".