6821381 has 8 divisors (see below), whose sum is σ = 7872384. Its totient is φ = 5789520.

The previous prime is 6821303. The next prime is 6821383. The reversal of 6821381 is 1831286.

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

It is a cyclic number.

It is not a de Polignac number, because 6821381 - 2¹⁴ = 6804997 is a prime.

It is a super-2 number, since 2×6821381² = 93062477494322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6821383) 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, 4010 + ... + 5451.

It is an arithmetic number, because the mean of its divisors is an integer number (984048).

Almost surely, 2^6821381 is an apocalyptic number.

It is an amenable number.

6821381 is a deficient number, since it is larger than the sum of its proper divisors (1051003).

6821381 is a wasteful number, since it uses less digits than its factorization.

6821381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9571.

The product of its digits is 2304, while the sum is 29.

The square root of 6821381 is about 2611.7773641718. Note that the first 3 decimals coincide. The cubic root of 6821381 is about 189.6520038262.

The spelling of 6821381 in words is "six million, eight hundred twenty-one thousand, three hundred eighty-one".