409819 has 4 divisors (see below), whose sum is σ = 433944. Its totient is φ = 385696.

The previous prime is 409817. The next prime is 409823. The reversal of 409819 is 918904.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 409819 - 2¹ = 409817 is a prime.

It is a super-2 number, since 2×409819² = 335903225522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (409813) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12037 + ... + 12070.

It is an arithmetic number, because the mean of its divisors is an integer number (108486).

2⁴⁰⁹⁸¹⁹ is an apocalyptic number.

409819 is a deficient number, since it is larger than the sum of its proper divisors (24125).

409819 is a wasteful number, since it uses less digits than its factorization.

409819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24124.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 409819 is about 640.1710708865. The cubic root of 409819 is about 74.2786547602.

It can be divided in two parts, 409 and 819, that multiplied together give a triangular number (334971 = T₈₁₈).

The spelling of 409819 in words is "four hundred nine thousand, eight hundred nineteen".