20840653 has 2 divisors, whose sum is σ = 20840654. Its totient is φ = 20840652.

The previous prime is 20840639. The next prime is 20840683. The reversal of 20840653 is 35604802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16670889 + 4169764 = 4083^2 + 2042^2 .

It is a cyclic number.

It is not a de Polignac number, because 20840653 - 2⁵ = 20840621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20840683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10420326 + 10420327.

It is an arithmetic number, because the mean of its divisors is an integer number (10420327).

Almost surely, 2^20840653 is an apocalyptic number.

It is an amenable number.

20840653 is a deficient number, since it is larger than the sum of its proper divisors (1).

20840653 is an equidigital number, since it uses as much as digits as its factorization.

20840653 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 20840653 is about 4565.1564047686. The cubic root of 20840653 is about 275.1928256437.

The spelling of 20840653 in words is "twenty million, eight hundred forty thousand, six hundred fifty-three".