66958234581 has 32 divisors (see below), whose sum is σ = 105434431488. Its totient is φ = 36988398720.

The previous prime is 66958234579. The next prime is 66958234613. The reversal of 66958234581 is 18543285966.

It is not a de Polignac number, because 66958234581 - 2¹ = 66958234579 is a prime.

It is a super-2 number, since 2×66958234581² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (57) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66958234561) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 566440 + ... + 674366.

It is an arithmetic number, because the mean of its divisors is an integer number (3294825984).

Almost surely, 2^66958234581 is an apocalyptic number.

It is an amenable number.

66958234581 is a deficient number, since it is larger than the sum of its proper divisors (38476196907).

66958234581 is a wasteful number, since it uses less digits than its factorization.

66958234581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108921.

The product of its digits is 12441600, while the sum is 57.

The spelling of 66958234581 in words is "sixty-six billion, nine hundred fifty-eight million, two hundred thirty-four thousand, five hundred eighty-one".