8021002666 has 4 divisors (see below), whose sum is σ = 12031504002. Its totient is φ = 4010501332.

The previous prime is 8021002663. The next prime is 8021002687. The reversal of 8021002666 is 6662001208.

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., 5694966225 + 2326036441 = 75465^2 + 48229^2 .

It is not an unprimeable number, because it can be changed into a prime (8021002663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2005250665 + ... + 2005250668.

Almost surely, 2^8021002666 is an apocalyptic number.

8021002666 is a deficient number, since it is larger than the sum of its proper divisors (4010501336).

8021002666 is a wasteful number, since it uses less digits than its factorization.

8021002666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4010501335.

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 8021002666 is about 89560.0506140991. The cubic root of 8021002666 is about 2001.7486927579.

The spelling of 8021002666 in words is "eight billion, twenty-one million, two thousand, six hundred sixty-six".