8491405 has 16 divisors (see below), whose sum is σ = 11052720. Its totient is φ = 6262464.

The previous prime is 8491391. The next prime is 8491409. The reversal of 8491405 is 5041948.

It is a happy number.

8491405 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 7946761 + 544644 = 2819^2 + 738^2 .

It is not a de Polignac number, because 8491405 - 2⁷ = 8491277 is a prime.

8491405 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8491409) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10599 + ... + 11371.

It is an arithmetic number, because the mean of its divisors is an integer number (690795).

Almost surely, 2^8491405 is an apocalyptic number.

It is an amenable number.

8491405 is a deficient number, since it is larger than the sum of its proper divisors (2561315).

8491405 is an equidigital number, since it uses as much as digits as its factorization.

8491405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 817 (or 791 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 8491405 is about 2914.0015442686. The cubic root of 8491405 is about 204.0139440039.

The spelling of 8491405 in words is "eight million, four hundred ninety-one thousand, four hundred five".