6665221331 has 4 divisors (see below), whose sum is σ = 7057293192. Its totient is φ = 6273149472.

The previous prime is 6665221319. The next prime is 6665221349. The reversal of 6665221331 is 1331225666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1331225666 = 2 ⋅665612833.

It is a cyclic number.

It is not a de Polignac number, because 6665221331 - 2¹⁸ = 6664959187 is a prime.

It is a super-2 number, since 2×6665221331² = 88850350782434823122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6665221291 and 6665221300.

It is not an unprimeable number, because it can be changed into a prime (6665221301) 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 in 3 ways as a sum of consecutive naturals, for example, 196035905 + ... + 196035938.

It is an arithmetic number, because the mean of its divisors is an integer number (1764323298).

Almost surely, 2^6665221331 is an apocalyptic number.

6665221331 is a deficient number, since it is larger than the sum of its proper divisors (392071861).

6665221331 is a wasteful number, since it uses less digits than its factorization.

6665221331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 392071860.

The product of its digits is 38880, while the sum is 35.

The square root of 6665221331 is about 81640.8067757785. The cubic root of 6665221331 is about 1881.9360366382.

Adding to 6665221331 its reverse (1331225666), we get a palindrome (7996446997).

The spelling of 6665221331 in words is "six billion, six hundred sixty-five million, two hundred twenty-one thousand, three hundred thirty-one".