6660355321 has 3 divisors (see below), whose sum is σ = 6660436933. Its totient is φ = 6660273710.

The previous prime is 6660355313. The next prime is 6660355327. The reversal of 6660355321 is 1235530666.

The square root of 6660355321 is 81611.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1235530666 = 2 ⋅617765333.

It is not a de Polignac number, because 6660355321 - 2³ = 6660355313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6660355327) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 40806 + ... + 122416.

Almost surely, 2^6660355321 is an apocalyptic number.

6660355321 is the 81611-st square number.

6660355321 is the 40806-th centered octagonal number.

It is an amenable number.

6660355321 is a deficient number, since it is larger than the sum of its proper divisors (81612).

6660355321 is an frugal number, since it uses more digits than its factorization.

6660355321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163222 (or 81611 counting only the distinct ones).

The product of its (nonzero) digits is 97200, while the sum is 37.

The cubic root of 6660355321 is about 1881.4779498753.

Adding to 6660355321 its reverse (1235530666), we get a palindrome (7895885987).

The spelling of 6660355321 in words is "six billion, six hundred sixty million, three hundred fifty-five thousand, three hundred twenty-one".