1021265563 has 2 divisors, whose sum is σ = 1021265564. Its totient is φ = 1021265562.

The previous prime is 1021265543. The next prime is 1021265587. The reversal of 1021265563 is 3655621201.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1021265563 - 2⁹ = 1021265051 is a prime.

It is not a weakly prime, because it can be changed into another prime (1021265543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510632781 + 510632782.

It is an arithmetic number, because the mean of its divisors is an integer number (510632782).

Almost surely, 2^1021265563 is an apocalyptic number.

1021265563 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021265563 is an equidigital number, since it uses as much as digits as its factorization.

1021265563 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10800, while the sum is 31.

The square root of 1021265563 is about 31957.2458606808. The cubic root of 1021265563 is about 1007.0388592130.

Adding to 1021265563 its reverse (3655621201), we get a palindrome (4676886764).

The spelling of 1021265563 in words is "one billion, twenty-one million, two hundred sixty-five thousand, five hundred sixty-three".