1801421 has 4 divisors (see below), whose sum is σ = 1826172. Its totient is φ = 1776672.

The previous prime is 1801411. The next prime is 1801433. The reversal of 1801421 is 1241081.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1297321 + 504100 = 1139^2 + 710^2 .

It is a cyclic number.

It is not a de Polignac number, because 1801421 - 2⁶ = 1801357 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1801421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1801411) 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, 12266 + ... + 12411.

It is an arithmetic number, because the mean of its divisors is an integer number (456543).

2^1801421 is an apocalyptic number.

It is an amenable number.

1801421 is a deficient number, since it is larger than the sum of its proper divisors (24751).

1801421 is an equidigital number, since it uses as much as digits as its factorization.

1801421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24750.

The product of its (nonzero) digits is 64, while the sum is 17.

The square root of 1801421 is about 1342.1702574562. The cubic root of 1801421 is about 121.6760418955.

It can be divided in two parts, 1801 and 421, that added together give a palindrome (2222).

The spelling of 1801421 in words is "one million, eight hundred one thousand, four hundred twenty-one".