1836421 has 4 divisors (see below), whose sum is σ = 1886092. Its totient is φ = 1786752.

The previous prime is 1836413. The next prime is 1836427. The reversal of 1836421 is 1246381.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1246381 = 19 ⋅65599.

It can be written as a sum of positive squares in 2 ways, for example, as 1079521 + 756900 = 1039^2 + 870^2 .

It is a cyclic number.

It is not a de Polignac number, because 1836421 - 2³ = 1836413 is a prime.

It is a Duffinian number.

1836421 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1836427) 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, 24780 + ... + 24853.

It is an arithmetic number, because the mean of its divisors is an integer number (471523).

2^1836421 is an apocalyptic number.

It is an amenable number.

1836421 is a deficient number, since it is larger than the sum of its proper divisors (49671).

1836421 is an equidigital number, since it uses as much as digits as its factorization.

1836421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49670.

The product of its digits is 1152, while the sum is 25.

The square root of 1836421 is about 1355.1461175829. The cubic root of 1836421 is about 122.4590116930.

The spelling of 1836421 in words is "one million, eight hundred thirty-six thousand, four hundred twenty-one".