21241811563 has 4 divisors (see below), whose sum is σ = 24276356080. Its totient is φ = 18207267048.

The previous prime is 21241811533. The next prime is 21241811573. The reversal of 21241811563 is 36511814212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21241811563 - 2⁹ = 21241811051 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21241811533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1517272248 + ... + 1517272261.

It is an arithmetic number, because the mean of its divisors is an integer number (6069089020).

Almost surely, 2^21241811563 is an apocalyptic number.

21241811563 is a deficient number, since it is larger than the sum of its proper divisors (3034544517).

21241811563 is an equidigital number, since it uses as much as digits as its factorization.

21241811563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3034544516.

The product of its digits is 11520, while the sum is 34.

The spelling of 21241811563 in words is "twenty-one billion, two hundred forty-one million, eight hundred eleven thousand, five hundred sixty-three".