66417501993 has 16 divisors (see below), whose sum is σ = 90750506112. Its totient is φ = 43182224000.

The previous prime is 66417501991. The next prime is 66417502009. The reversal of 66417501993 is 39910571466.

It is a cyclic number.

It is not a de Polignac number, because 66417501993 - 2¹ = 66417501991 is a prime.

It is a super-2 number, since 2×66417501993² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66417501991) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 233863 + ... + 433043.

It is an arithmetic number, because the mean of its divisors is an integer number (5671906632).

Almost surely, 2^66417501993 is an apocalyptic number.

It is an amenable number.

66417501993 is a deficient number, since it is larger than the sum of its proper divisors (24333004119).

66417501993 is a wasteful number, since it uses less digits than its factorization.

66417501993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201936.

The product of its (nonzero) digits is 1224720, while the sum is 51.

The spelling of 66417501993 in words is "sixty-six billion, four hundred seventeen million, five hundred one thousand, nine hundred ninety-three".