409491 has 12 divisors (see below), whose sum is σ = 597168. Its totient is φ = 270384.

The previous prime is 409483. The next prime is 409499. The reversal of 409491 is 194904.

It is an interprime number because it is at equal distance from previous prime (409483) and next prime (409499).

It is not a de Polignac number, because 409491 - 2³ = 409483 is a prime.

It is not an unprimeable number, because it can be changed into a prime (409499) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1426 + ... + 1688.

It is an arithmetic number, because the mean of its divisors is an integer number (49764).

2⁴⁰⁹⁴⁹¹ is an apocalyptic number.

409491 is a deficient number, since it is larger than the sum of its proper divisors (187677).

409491 is a wasteful number, since it uses less digits than its factorization.

409491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442 (or 439 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 409491 is about 639.9148380839. The cubic root of 409491 is about 74.2588330817.

It can be divided in two parts, 409 and 491, that added together give a square (900 = 30²).

The spelling of 409491 in words is "four hundred nine thousand, four hundred ninety-one".