6866021 has 2 divisors, whose sum is σ = 6866022. Its totient is φ = 6866020.

The previous prime is 6866017. The next prime is 6866039. The reversal of 6866021 is 1206686.

6866021 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6604900 + 261121 = 2570^2 + 511^2 .

It is a cyclic number.

It is not a de Polignac number, because 6866021 - 2² = 6866017 is a prime.

It is a Chen prime.

It is equal to p₄₆₈₁₁₉ and since 6866021 and 468119 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6866051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3433010 + 3433011.

It is an arithmetic number, because the mean of its divisors is an integer number (3433011).

Almost surely, 2^6866021 is an apocalyptic number.

It is an amenable number.

6866021 is a deficient number, since it is larger than the sum of its proper divisors (1).

6866021 is an equidigital number, since it uses as much as digits as its factorization.

6866021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 6866021 is about 2620.3093328842. The cubic root of 6866021 is about 190.0648070707.

The spelling of 6866021 in words is "six million, eight hundred sixty-six thousand, twenty-one".