1819945 has 4 divisors (see below), whose sum is σ = 2183940. Its totient is φ = 1455952.

The previous prime is 1819933. The next prime is 1819957. The reversal of 1819945 is 5499181.

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

It is an interprime number because it is at equal distance from previous prime (1819933) and next prime (1819957).

It can be written as a sum of positive squares in 2 ways, for example, as 670761 + 1149184 = 819^2 + 1072^2 .

It is a cyclic number.

It is not a de Polignac number, because 1819945 - 2⁵ = 1819913 is a prime.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 181990 + ... + 181999.

It is an arithmetic number, because the mean of its divisors is an integer number (545985).

2^1819945 is an apocalyptic number.

It is an amenable number.

1819945 is a deficient number, since it is larger than the sum of its proper divisors (363995).

1819945 is an equidigital number, since it uses as much as digits as its factorization.

1819945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 363994.

The product of its digits is 12960, while the sum is 37.

The square root of 1819945 is about 1349.0533718130. The cubic root of 1819945 is about 122.0916850886.

The spelling of 1819945 in words is "one million, eight hundred nineteen thousand, nine hundred forty-five".