409989 has 8 divisors (see below), whose sum is σ = 578880. Its totient is φ = 257216.

The previous prime is 409987. The next prime is 409993. The reversal of 409989 is 989904.

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

It is a cyclic number.

It is not a de Polignac number, because 409989 - 2¹ = 409987 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (409987) 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 7 ways as a sum of consecutive naturals, for example, 3969 + ... + 4070.

It is an arithmetic number, because the mean of its divisors is an integer number (72360).

2⁴⁰⁹⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

409989 is a deficient number, since it is larger than the sum of its proper divisors (168891).

409989 is a wasteful number, since it uses less digits than its factorization.

409989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8059.

The product of its (nonzero) digits is 23328, while the sum is 39.

The square root of 409989 is about 640.3038341288. The cubic root of 409989 is about 74.2889240301.

The spelling of 409989 in words is "four hundred nine thousand, nine hundred eighty-nine".