66862193581 has 8 divisors (see below), whose sum is σ = 68704878104. Its totient is φ = 65021382720.

The previous prime is 66862193557. The next prime is 66862193647. The reversal of 66862193581 is 18539126866.

It can be written as a sum of positive squares in 4 ways, for example, as 13985191081 + 52877002500 = 118259^2 + 229950^2 .

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 66862193581 - 2¹¹ = 66862191533 is a prime.

It is a super-2 number, since 2×66862193581² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66862193501) 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, 395910 + ... + 538951.

It is an arithmetic number, because the mean of its divisors is an integer number (8588109763).

Almost surely, 2^66862193581 is an apocalyptic number.

It is an amenable number.

66862193581 is a deficient number, since it is larger than the sum of its proper divisors (1842684523).

66862193581 is a wasteful number, since it uses less digits than its factorization.

66862193581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 936831.

The product of its digits is 3732480, while the sum is 55.

The spelling of 66862193581 in words is "sixty-six billion, eight hundred sixty-two million, one hundred ninety-three thousand, five hundred eighty-one".