1801409 has 4 divisors (see below), whose sum is σ = 1896240. Its totient is φ = 1706580.

The previous prime is 1801403. The next prime is 1801411. The reversal of 1801409 is 9041081.

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 not a de Polignac number, because 1801409 - 2²⁰ = 752833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1801403) 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, 47387 + ... + 47424.

It is an arithmetic number, because the mean of its divisors is an integer number (474060).

2^1801409 is an apocalyptic number.

1801409 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1801409 is a deficient number, since it is larger than the sum of its proper divisors (94831).

1801409 is an equidigital number, since it uses as much as digits as its factorization.

1801409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94830.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 1801409 is about 1342.1657870770. The cubic root of 1801409 is about 121.6757717170.

The spelling of 1801409 in words is "one million, eight hundred one thousand, four hundred nine".