20720653 has 2 divisors, whose sum is σ = 20720654. Its totient is φ = 20720652.

The previous prime is 20720633. The next prime is 20720681. The reversal of 20720653 is 35602702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12299049 + 8421604 = 3507^2 + 2902^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20720653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20720633) 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, 10360326 + 10360327.

It is an arithmetic number, because the mean of its divisors is an integer number (10360327).

Almost surely, 2^20720653 is an apocalyptic number.

It is an amenable number.

20720653 is a deficient number, since it is larger than the sum of its proper divisors (1).

20720653 is an equidigital number, since it uses as much as digits as its factorization.

20720653 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2520, while the sum is 25.

The square root of 20720653 is about 4551.9943980633. The cubic root of 20720653 is about 274.6636239792.

The spelling of 20720653 in words is "twenty million, seven hundred twenty thousand, six hundred fifty-three".