409640 has 96 divisors (see below), whose sum is σ = 1231200. Its totient is φ = 120960.

The previous prime is 409639. The next prime is 409657. The reversal of 409640 is 46904.

It is a nialpdrome in base 14.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 409640.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21551 + ... + 21569.

It is an arithmetic number, because the mean of its divisors is an integer number (12825).

2⁴⁰⁹⁶⁴⁰ is an apocalyptic number.

409640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 409640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (615600).

409640 is an abundant number, since it is smaller than the sum of its proper divisors (821560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

409640 is a wasteful number, since it uses less digits than its factorization.

409640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55 (or 44 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 409640 is about 640.0312492371. The cubic root of 409640 is about 74.2678387533.

The spelling of 409640 in words is "four hundred nine thousand, six hundred forty".