2663821 has 4 divisors (see below), whose sum is σ = 2667100. Its totient is φ = 2660544.

The previous prime is 2663813. The next prime is 2663827. The reversal of 2663821 is 1283662.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 1653796 + 1010025 = 1286^2 + 1005^2 .

It is a cyclic number.

It is not a de Polignac number, because 2663821 - 2³ = 2663813 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2663821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2663827) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 595 + ... + 2383.

It is an arithmetic number, because the mean of its divisors is an integer number (666775).

2^2663821 is an apocalyptic number.

It is an amenable number.

2663821 is a deficient number, since it is larger than the sum of its proper divisors (3279).

2663821 is a wasteful number, since it uses less digits than its factorization.

2663821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3278.

The product of its digits is 3456, while the sum is 28.

The square root of 2663821 is about 1632.1216253699. The cubic root of 2663821 is about 138.6229104371.

The spelling of 2663821 in words is "two million, six hundred sixty-three thousand, eight hundred twenty-one".