1821845663 has 8 divisors (see below), whose sum is σ = 2073879936. Its totient is φ = 1584213400.

The previous prime is 1821845657. The next prime is 1821845671. The reversal of 1821845663 is 3665481281.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1821845663 - 2²⁶ = 1754736799 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821847663) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 3600233 + ... + 3600738.

It is an arithmetic number, because the mean of its divisors is an integer number (259234992).

Almost surely, 2^1821845663 is an apocalyptic number.

1821845663 is a deficient number, since it is larger than the sum of its proper divisors (252034273).

1821845663 is a wasteful number, since it uses less digits than its factorization.

1821845663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7201005.

The product of its digits is 276480, while the sum is 44.

The square root of 1821845663 is about 42683.0840380589. The cubic root of 1821845663 is about 1221.3417252877.

The spelling of 1821845663 in words is "one billion, eight hundred twenty-one million, eight hundred forty-five thousand, six hundred sixty-three".