409825 has 18 divisors (see below), whose sum is σ = 555954. Its totient is φ = 299520.

The previous prime is 409823. The next prime is 409831. The reversal of 409825 is 528904.

It is a happy number.

It can be written as a sum of positive squares in 9 ways, for example, as 271441 + 138384 = 521^2 + 372^2 .

It is not a de Polignac number, because 409825 - 2¹ = 409823 is a prime.

It is an Ulam number.

It is a Duffinian number.

409825 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 409793 and 409802.

It is not an unprimeable number, because it can be changed into a prime (409823) 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 17 ways as a sum of consecutive naturals, for example, 4177 + ... + 4273.

2⁴⁰⁹⁸²⁵ is an apocalyptic number.

It is an amenable number.

409825 is a deficient number, since it is larger than the sum of its proper divisors (146129).

409825 is a wasteful number, since it uses less digits than its factorization.

409825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133 (or 115 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 409825 is about 640.1757571167. The cubic root of 409825 is about 74.2790172534.

The spelling of 409825 in words is "four hundred nine thousand, eight hundred twenty-five".