1666842583426 has 4 divisors (see below), whose sum is σ = 2500263875142. Its totient is φ = 833421291712.

The previous prime is 1666842583421. The next prime is 1666842583453. The reversal of 1666842583426 is 6243852486661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 943619902801 + 723222680625 = 971401^2 + 850425^2 .

It is not an unprimeable number, because it can be changed into a prime (1666842583421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 416710645855 + ... + 416710645858.

Almost surely, 2^{1666842583426} is an apocalyptic number.

1666842583426 is a deficient number, since it is larger than the sum of its proper divisors (833421291716).

1666842583426 is an equidigital number, since it uses as much as digits as its factorization.

1666842583426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 833421291715.

The product of its digits is 79626240, while the sum is 61.

The spelling of 1666842583426 in words is "one trillion, six hundred sixty-six billion, eight hundred forty-two million, five hundred eighty-three thousand, four hundred twenty-six".