20655563 has 2 divisors, whose sum is σ = 20655564. Its totient is φ = 20655562.

The previous prime is 20655559. The next prime is 20655619. The reversal of 20655563 is 36555602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20655563 - 2² = 20655559 is a prime.

It is not a weakly prime, because it can be changed into another prime (20655553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10327781 + 10327782.

It is an arithmetic number, because the mean of its divisors is an integer number (10327782).

Almost surely, 2^20655563 is an apocalyptic number.

20655563 is a deficient number, since it is larger than the sum of its proper divisors (1).

20655563 is an equidigital number, since it uses as much as digits as its factorization.

20655563 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27000, while the sum is 32.

The square root of 20655563 is about 4544.8391610705. The cubic root of 20655563 is about 274.3757210837.

The spelling of 20655563 in words is "twenty million, six hundred fifty-five thousand, five hundred sixty-three".