6406861 has 2 divisors, whose sum is σ = 6406862. Its totient is φ = 6406860.

The previous prime is 6406849. The next prime is 6406867. The reversal of 6406861 is 1686046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6405961 + 900 = 2531^2 + 30^2 .

It is a cyclic number.

It is not a de Polignac number, because 6406861 - 2²¹ = 4309709 is a prime.

It is equal to p₄₃₈₈₄₄ and since 6406861 and 438844 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 (6406867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3203430 + 3203431.

It is an arithmetic number, because the mean of its divisors is an integer number (3203431).

Almost surely, 2^6406861 is an apocalyptic number.

It is an amenable number.

6406861 is a deficient number, since it is larger than the sum of its proper divisors (1).

6406861 is an equidigital number, since it uses as much as digits as its factorization.

6406861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 6406861 is about 2531.1777890934. The cubic root of 6406861 is about 185.7298753608.

The spelling of 6406861 in words is "six million, four hundred six thousand, eight hundred sixty-one".