1820111 has 2 divisors, whose sum is σ = 1820112. Its totient is φ = 1820110.

The previous prime is 1820089. The next prime is 1820123. The reversal of 1820111 is 1110281.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1820111 - 2⁶ = 1820047 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1820171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910055 + 910056.

It is an arithmetic number, because the mean of its divisors is an integer number (910056).

2^1820111 is an apocalyptic number.

1820111 is a deficient number, since it is larger than the sum of its proper divisors (1).

1820111 is an equidigital number, since it uses as much as digits as its factorization.

1820111 is an evil number, because the sum of its binary digits is even.

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

The square root of 1820111 is about 1349.1148950330. The cubic root of 1820111 is about 122.0953970329.

Adding to 1820111 its reverse (1110281), we get a palindrome (2930392).

The spelling of 1820111 in words is "one million, eight hundred twenty thousand, one hundred eleven".