1821175145 has 4 divisors (see below), whose sum is σ = 2185410180. Its totient is φ = 1456940112.

The previous prime is 1821175123. The next prime is 1821175157. The reversal of 1821175145 is 5415711281.

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

It can be written as a sum of positive squares in 2 ways, for example, as 418447936 + 1402727209 = 20456^2 + 37453^2 .

It is a cyclic number.

It is not a de Polignac number, because 1821175145 - 2¹⁴ = 1821158761 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 182117510 + ... + 182117519.

It is an arithmetic number, because the mean of its divisors is an integer number (546352545).

Almost surely, 2^1821175145 is an apocalyptic number.

It is an amenable number.

1821175145 is a deficient number, since it is larger than the sum of its proper divisors (364235035).

1821175145 is an equidigital number, since it uses as much as digits as its factorization.

1821175145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364235034.

The product of its digits is 11200, while the sum is 35.

The square root of 1821175145 is about 42675.2287047182. The cubic root of 1821175145 is about 1221.1918713757.

The spelling of 1821175145 in words is "one billion, eight hundred twenty-one million, one hundred seventy-five thousand, one hundred forty-five".