6409861 has 4 divisors (see below), whose sum is σ = 6419232. Its totient is φ = 6400492.

The previous prime is 6409849. The next prime is 6409883. The reversal of 6409861 is 1689046.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1689046 = 2 ⋅844523.

It is a cyclic number.

It is not a de Polignac number, because 6409861 - 2¹³ = 6401669 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6406861) 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 in 3 ways as a sum of consecutive naturals, for example, 3571 + ... + 5056.

It is an arithmetic number, because the mean of its divisors is an integer number (1604808).

Almost surely, 2^6409861 is an apocalyptic number.

It is an amenable number.

6409861 is a deficient number, since it is larger than the sum of its proper divisors (9371).

6409861 is an equidigital number, since it uses as much as digits as its factorization.

6409861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9370.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 6409861 is about 2531.7703292360. The cubic root of 6409861 is about 185.7588600529.

It can be divided in two parts, 640 and 9861, that added together give a palindrome (10501).

The spelling of 6409861 in words is "six million, four hundred nine thousand, eight hundred sixty-one".