2163821 has 8 divisors (see below), whose sum is σ = 2373600. Its totient is φ = 1956240.

The previous prime is 2163809. The next prime is 2163823. The reversal of 2163821 is 1283612.

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

It is not a de Polignac number, because 2163821 - 2⁶ = 2163757 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2163823) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2090 + ... + 2948.

It is an arithmetic number, because the mean of its divisors is an integer number (296700).

2^2163821 is an apocalyptic number.

It is an amenable number.

2163821 is a deficient number, since it is larger than the sum of its proper divisors (209779).

2163821 is a wasteful number, since it uses less digits than its factorization.

2163821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1099.

The product of its digits is 576, while the sum is 23.

The square root of 2163821 is about 1470.9932018878. The cubic root of 2163821 is about 129.3422596017.

The spelling of 2163821 in words is "two million, one hundred sixty-three thousand, eight hundred twenty-one".