7943571666 has 20 divisors (see below), whose sum is σ = 17799485022. Its totient is φ = 2647857168.

The previous prime is 7943571653. The next prime is 7943571673. The reversal of 7943571666 is 6661753497.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 7660625625 + 282946041 = 87525^2 + 16821^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

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 in 9 ways as a sum of consecutive naturals, for example, 24517035 + ... + 24517358.

Almost surely, 2^7943571666 is an apocalyptic number.

7943571666 is an abundant number, since it is smaller than the sum of its proper divisors (9855913356).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7943571666 is a wasteful number, since it uses less digits than its factorization.

7943571666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49034407 (or 49034398 counting only the distinct ones).

The product of its digits is 5715360, while the sum is 54.

The square root of 7943571666 is about 89126.7169035189. The cubic root of 7943571666 is about 1995.2865392035.

The spelling of 7943571666 in words is "seven billion, nine hundred forty-three million, five hundred seventy-one thousand, six hundred sixty-six".