1821101 has 2 divisors, whose sum is σ = 1821102. Its totient is φ = 1821100.

The previous prime is 1821067. The next prime is 1821107. The reversal of 1821101 is 1011281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1623076 + 198025 = 1274^2 + 445^2 .

It is an emirp because it is prime and its reverse (1011281) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1821101 - 2⁶ = 1821037 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1821107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910550 + 910551.

It is an arithmetic number, because the mean of its divisors is an integer number (910551).

2^1821101 is an apocalyptic number.

It is an amenable number.

1821101 is a deficient number, since it is larger than the sum of its proper divisors (1).

1821101 is an equidigital number, since it uses as much as digits as its factorization.

1821101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 14.

The square root of 1821101 is about 1349.4817523776. The cubic root of 1821101 is about 122.1175298469.

Adding to 1821101 its reverse (1011281), we get a palindrome (2832382).

It can be divided in two parts, 1821 and 101, that multiplied together give a triangular number (183921 = T₆₀₆).

The spelling of 1821101 in words is "one million, eight hundred twenty-one thousand, one hundred one".