1821013 has 2 divisors, whose sum is σ = 1821014. Its totient is φ = 1821012.

The previous prime is 1820999. The next prime is 1821019. The reversal of 1821013 is 3101281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1532644 + 288369 = 1238^2 + 537^2 .

It is a cyclic number.

It is not a de Polignac number, because 1821013 - 2⁹ = 1820501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1821019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910506 + 910507.

It is an arithmetic number, because the mean of its divisors is an integer number (910507).

2^1821013 is an apocalyptic number.

It is an amenable number.

1821013 is a deficient number, since it is larger than the sum of its proper divisors (1).

1821013 is an equidigital number, since it uses as much as digits as its factorization.

1821013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 16.

The square root of 1821013 is about 1349.4491468744. The cubic root of 1821013 is about 122.1155628105.

Adding to 1821013 its reverse (3101281), we get a palindrome (4922294).

The spelling of 1821013 in words is "one million, eight hundred twenty-one thousand, thirteen".