2649821 has 2 divisors, whose sum is σ = 2649822. Its totient is φ = 2649820.

The previous prime is 2649811. The next prime is 2649851. The reversal of 2649821 is 1289462.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1406596 + 1243225 = 1186^2 + 1115^2 .

It is a cyclic number.

It is not a de Polignac number, because 2649821 - 2¹⁴ = 2633437 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2649811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1324910 + 1324911.

It is an arithmetic number, because the mean of its divisors is an integer number (1324911).

2^2649821 is an apocalyptic number.

It is an amenable number.

2649821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2649821 is an equidigital number, since it uses as much as digits as its factorization.

2649821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6912, while the sum is 32.

The square root of 2649821 is about 1627.8270792686. The cubic root of 2649821 is about 138.3796345066.

The spelling of 2649821 in words is "two million, six hundred forty-nine thousand, eight hundred twenty-one".