1821169465 has 4 divisors (see below), whose sum is σ = 2185403364. Its totient is φ = 1456935568.

The previous prime is 1821169439. The next prime is 1821169487. The reversal of 1821169465 is 5649611281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5649611281 = 16073 ⋅351497.

It can be written as a sum of positive squares in 2 ways, for example, as 514563856 + 1306605609 = 22684^2 + 36147^2 .

It is a cyclic number.

It is not a de Polignac number, because 1821169465 - 2¹³ = 1821161273 is a prime.

It is a Duffinian number.

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, 182116942 + ... + 182116951.

It is an arithmetic number, because the mean of its divisors is an integer number (546350841).

Almost surely, 2^1821169465 is an apocalyptic number.

It is an amenable number.

1821169465 is a deficient number, since it is larger than the sum of its proper divisors (364233899).

1821169465 is an equidigital number, since it uses as much as digits as its factorization.

1821169465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364233898.

The product of its digits is 103680, while the sum is 43.

The square root of 1821169465 is about 42675.1621555209. The cubic root of 1821169465 is about 1221.1906017967.

The spelling of 1821169465 in words is "one billion, eight hundred twenty-one million, one hundred sixty-nine thousand, four hundred sixty-five".