6821879 has 4 divisors (see below), whose sum is σ = 7223184. Its totient is φ = 6420576.

The previous prime is 6821863. The next prime is 6821897. The reversal of 6821879 is 9781286.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 6821879 - 2⁴ = 6821863 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 (6821809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 200627 + ... + 200660.

It is an arithmetic number, because the mean of its divisors is an integer number (1805796).

Almost surely, 2^6821879 is an apocalyptic number.

6821879 is a deficient number, since it is larger than the sum of its proper divisors (401305).

6821879 is a wasteful number, since it uses less digits than its factorization.

6821879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 401304.

The product of its digits is 48384, while the sum is 41.

The square root of 6821879 is about 2611.8726998076. The cubic root of 6821879 is about 189.6566189425.

The spelling of 6821879 in words is "six million, eight hundred twenty-one thousand, eight hundred seventy-nine".