1809481 has 2 divisors, whose sum is σ = 1809482. Its totient is φ = 1809480.

The previous prime is 1809461. The next prime is 1809487. The reversal of 1809481 is 1849081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1742400 + 67081 = 1320^2 + 259^2 .

It is a cyclic number.

It is not a de Polignac number, because 1809481 - 2⁵ = 1809449 is a prime.

It is a super-2 number, since 2×1809481² = 6548442978722, which contains 22 as substring.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (1809487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 904740 + 904741.

It is an arithmetic number, because the mean of its divisors is an integer number (904741).

2^1809481 is an apocalyptic number.

It is an amenable number.

1809481 is a deficient number, since it is larger than the sum of its proper divisors (1).

1809481 is an equidigital number, since it uses as much as digits as its factorization.

1809481 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 1809481 is about 1345.1695060475. The cubic root of 1809481 is about 121.8572414186.

The spelling of 1809481 in words is "one million, eight hundred nine thousand, four hundred eighty-one".