8409861 has 6 divisors (see below), whose sum is σ = 12147590. Its totient is φ = 5606568.

The previous prime is 8409857. The next prime is 8409871. The reversal of 8409861 is 1689048.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 4284900 + 4124961 = 2070^2 + 2031^2 .

It is not a de Polignac number, because 8409861 - 2² = 8409857 is a prime.

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 (8409871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 467206 + ... + 467223.

Almost surely, 2^8409861 is an apocalyptic number.

It is an amenable number.

8409861 is a deficient number, since it is larger than the sum of its proper divisors (3737729).

8409861 is a wasteful number, since it uses less digits than its factorization.

8409861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 934435 (or 934432 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 8409861 is about 2899.9760343837. The cubic root of 8409861 is about 203.3587853714.

It can be divided in two parts, 840 and 9861, that added together give a palindrome (10701).

The spelling of 8409861 in words is "eight million, four hundred nine thousand, eight hundred sixty-one".