6660321 has 8 divisors (see below), whose sum is σ = 8893824. Its totient is φ = 4433520.

The previous prime is 6660307. The next prime is 6660337. The reversal of 6660321 is 1230666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 6660321 - 2⁷ = 6660193 is a prime.

It is a nialpdrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 6660291 and 6660300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6660371) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1515 + ... + 3951.

It is an arithmetic number, because the mean of its divisors is an integer number (1111728).

Almost surely, 2^6660321 is an apocalyptic number.

It is an amenable number.

6660321 is a deficient number, since it is larger than the sum of its proper divisors (2233503).

6660321 is a wasteful number, since it uses less digits than its factorization.

6660321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3351.

The product of its (nonzero) digits is 1296, while the sum is 24.

The square root of 6660321 is about 2580.7597718501. The cubic root of 6660321 is about 188.1474718100.

Adding to 6660321 its reverse (1230666), we get a palindrome (7890987).

The spelling of 6660321 in words is "six million, six hundred sixty thousand, three hundred twenty-one".