402409 has 4 divisors (see below), whose sum is σ = 459904. Its totient is φ = 344916.

The previous prime is 402403. The next prime is 402419. The reversal of 402409 is 904204.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-402409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (402403) 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, 28737 + ... + 28750.

It is an arithmetic number, because the mean of its divisors is an integer number (114976).

2⁴⁰²⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

402409 is a deficient number, since it is larger than the sum of its proper divisors (57495).

402409 is an equidigital number, since it uses as much as digits as its factorization.

402409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57494.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 402409 is about 634.3571549214. The cubic root of 402409 is about 73.8282478899.

The spelling of 402409 in words is "four hundred two thousand, four hundred nine".