1821361 has 4 divisors (see below), whose sum is σ = 1829412. Its totient is φ = 1813312.

The previous prime is 1821353. The next prime is 1821371. The reversal of 1821361 is 1631281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1631281 = 89 ⋅18329.

It can be written as a sum of positive squares in 2 ways, for example, as 118336 + 1703025 = 344^2 + 1305^2 .

It is a cyclic number.

It is not a de Polignac number, because 1821361 - 2³ = 1821353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1821311) 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, 3676 + ... + 4141.

It is an arithmetic number, because the mean of its divisors is an integer number (457353).

2^1821361 is an apocalyptic number.

It is an amenable number.

1821361 is a deficient number, since it is larger than the sum of its proper divisors (8051).

1821361 is an equidigital number, since it uses as much as digits as its factorization.

1821361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8050.

The product of its digits is 288, while the sum is 22.

The square root of 1821361 is about 1349.5780822168. The cubic root of 1821361 is about 122.1233411751.

The spelling of 1821361 in words is "one million, eight hundred twenty-one thousand, three hundred sixty-one".