5663821 has 2 divisors, whose sum is σ = 5663822. Its totient is φ = 5663820.

The previous prime is 5663807. The next prime is 5663887. The reversal of 5663821 is 1283665.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4247721 + 1416100 = 2061^2 + 1190^2 .

It is a cyclic number.

It is not a de Polignac number, because 5663821 - 2²¹ = 3566669 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5663321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2831910 + 2831911.

It is an arithmetic number, because the mean of its divisors is an integer number (2831911).

Almost surely, 2^5663821 is an apocalyptic number.

It is an amenable number.

5663821 is a deficient number, since it is larger than the sum of its proper divisors (1).

5663821 is an equidigital number, since it uses as much as digits as its factorization.

5663821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 31.

The square root of 5663821 is about 2379.8783582360. The cubic root of 5663821 is about 178.2528599174.

The spelling of 5663821 in words is "five million, six hundred sixty-three thousand, eight hundred twenty-one".