1801111 has 4 divisors (see below), whose sum is σ = 1939672. Its totient is φ = 1662552.

The previous prime is 1801109. The next prime is 1801117. The reversal of 1801111 is 1111081.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1801111 - 2¹ = 1801109 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 138547 = 1801111 / (1 + 8 + 0 + 1 + 1 + 1 + 1).

It is a Duffinian number.

1801111 is a modest number, since divided by 1111 gives 180 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 1801091 and 1801100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1801117) 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, 69261 + ... + 69286.

It is an arithmetic number, because the mean of its divisors is an integer number (484918).

2^1801111 is an apocalyptic number.

1801111 is a deficient number, since it is larger than the sum of its proper divisors (138561).

1801111 is a wasteful number, since it uses less digits than its factorization.

1801111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138560.

The product of its (nonzero) digits is 8, while the sum is 13.

The square root of 1801111 is about 1342.0547678839. The cubic root of 1801111 is about 121.6690618990.

Adding to 1801111 its reverse (1111081), we get a palindrome (2912192).

The spelling of 1801111 in words is "one million, eight hundred one thousand, one hundred eleven".