6681321 has 6 divisors (see below), whose sum is σ = 9650810. Its totient is φ = 4454208.

The previous prime is 6681287. The next prime is 6681329. The reversal of 6681321 is 1231866.

It can be written as a sum of positive squares in only one way, i.e., 4247721 + 2433600 = 2061^2 + 1560^2 .

It is not a de Polignac number, because 6681321 - 2⁷ = 6681193 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6681329) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 371176 + ... + 371193.

Almost surely, 2^6681321 is an apocalyptic number.

It is an amenable number.

6681321 is a deficient number, since it is larger than the sum of its proper divisors (2969489).

6681321 is a wasteful number, since it uses less digits than its factorization.

6681321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 742375 (or 742372 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 6681321 is about 2584.8251391535. The cubic root of 6681321 is about 188.3450074124.

The spelling of 6681321 in words is "six million, six hundred eighty-one thousand, three hundred twenty-one".