21120044243 has 4 divisors (see below), whose sum is σ = 21131772888. Its totient is φ = 21108315600.

The previous prime is 21120044227. The next prime is 21120044269. The reversal of 21120044243 is 34244002112.

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 21120044243 - 2⁴ = 21120044227 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21120044443) 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 in 3 ways as a sum of consecutive naturals, for example, 5861621 + ... + 5865222.

It is an arithmetic number, because the mean of its divisors is an integer number (5282943222).

Almost surely, 2^21120044243 is an apocalyptic number.

21120044243 is a deficient number, since it is larger than the sum of its proper divisors (11728645).

21120044243 is a wasteful number, since it uses less digits than its factorization.

21120044243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11728644.

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21120044243 its reverse (34244002112), we get a palindrome (55364046355).

The spelling of 21120044243 in words is "twenty-one billion, one hundred twenty million, forty-four thousand, two hundred forty-three".