21750563 has 2 divisors, whose sum is σ = 21750564. Its totient is φ = 21750562.

The previous prime is 21750529. The next prime is 21750629. The reversal of 21750563 is 36505712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21750563 - 2¹² = 21746467 is a prime.

It is not a weakly prime, because it can be changed into another prime (21750503) 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, 10875281 + 10875282.

It is an arithmetic number, because the mean of its divisors is an integer number (10875282).

Almost surely, 2^21750563 is an apocalyptic number.

21750563 is a deficient number, since it is larger than the sum of its proper divisors (1).

21750563 is an equidigital number, since it uses as much as digits as its factorization.

21750563 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6300, while the sum is 29.

The square root of 21750563 is about 4663.7498860895. The cubic root of 21750563 is about 279.1409170676.

The spelling of 21750563 in words is "twenty-one million, seven hundred fifty thousand, five hundred sixty-three".