820203563 has 2 divisors, whose sum is σ = 820203564. Its totient is φ = 820203562.

The previous prime is 820203551. The next prime is 820203599. The reversal of 820203563 is 365302028.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 820203563 - 2⁴ = 820203547 is a prime.

It is equal to p_42131396 and since 820203563 and 42131396 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (820203463) 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, 410101781 + 410101782.

It is an arithmetic number, because the mean of its divisors is an integer number (410101782).

Almost surely, 2^820203563 is an apocalyptic number.

820203563 is a deficient number, since it is larger than the sum of its proper divisors (1).

820203563 is an equidigital number, since it uses as much as digits as its factorization.

820203563 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 820203563 is about 28639.1962701470. The cubic root of 820203563 is about 936.0676083308.

The spelling of 820203563 in words is "eight hundred twenty million, two hundred three thousand, five hundred sixty-three".