1801901 has 2 divisors, whose sum is σ = 1801902. Its totient is φ = 1801900.

The previous prime is 1801897. The next prime is 1801907. The reversal of 1801901 is 1091081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1525225 + 276676 = 1235^2 + 526^2 .

It is a cyclic number.

It is not a de Polignac number, because 1801901 - 2² = 1801897 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1801907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 900950 + 900951.

It is an arithmetic number, because the mean of its divisors is an integer number (900951).

2^1801901 is an apocalyptic number.

It is an amenable number.

1801901 is a deficient number, since it is larger than the sum of its proper divisors (1).

1801901 is an equidigital number, since it uses as much as digits as its factorization.

1801901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 20.

The square root of 1801901 is about 1342.3490604161. The cubic root of 1801901 is about 121.6868480523.

Adding to 1801901 its reverse (1091081), we get a palindrome (2892982).

It can be divided in two parts, 1801 and 901, that multiplied together give a triangular number (1622701 = T₁₈₀₁).

The spelling of 1801901 in words is "one million, eight hundred one thousand, nine hundred one".