408891 has 8 divisors (see below), whose sum is σ = 623104. Its totient is φ = 233640.

The previous prime is 408869. The next prime is 408911. The reversal of 408891 is 198804.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 408891 - 2⁷ = 408763 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 408891.

It is not an unprimeable number, because it can be changed into a prime (408841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9715 + ... + 9756.

It is an arithmetic number, because the mean of its divisors is an integer number (77888).

2⁴⁰⁸⁸⁹¹ is an apocalyptic number.

408891 is a deficient number, since it is larger than the sum of its proper divisors (214213).

408891 is a wasteful number, since it uses less digits than its factorization.

408891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19481.

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 408891 is about 639.4458538453. The cubic root of 408891 is about 74.2225465057. Note that the first 3 decimals are identical.

The spelling of 408891 in words is "four hundred eight thousand, eight hundred ninety-one".