1808421 has 8 divisors (see below), whose sum is σ = 2516160. Its totient is φ = 1153152.

The previous prime is 1808399. The next prime is 1808431. The reversal of 1808421 is 1248081.

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

It is not a de Polignac number, because 1808421 - 2⁷ = 1808293 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1808391 and 1808400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1808431) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13036 + ... + 13173.

It is an arithmetic number, because the mean of its divisors is an integer number (314520).

2^1808421 is an apocalyptic number.

It is an amenable number.

1808421 is a deficient number, since it is larger than the sum of its proper divisors (707739).

1808421 is a wasteful number, since it uses less digits than its factorization.

1808421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26235.

The product of its (nonzero) digits is 512, while the sum is 24.

The square root of 1808421 is about 1344.7754459388. The cubic root of 1808421 is about 121.8334419781.

The spelling of 1808421 in words is "one million, eight hundred eight thousand, four hundred twenty-one".