21022003243 has 4 divisors (see below), whose sum is σ = 21936003408. Its totient is φ = 20108003080.

The previous prime is 21022003181. The next prime is 21022003333. The reversal of 21022003243 is 34230022012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21022003243 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21022003243.

It is not an unprimeable number, because it can be changed into a prime (21022003643) 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 in 3 ways as a sum of consecutive naturals, for example, 457000048 + ... + 457000093.

It is an arithmetic number, because the mean of its divisors is an integer number (5484000852).

Almost surely, 2^21022003243 is an apocalyptic number.

21022003243 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21022003243 is a deficient number, since it is larger than the sum of its proper divisors (914000165).

21022003243 is an equidigital number, since it uses as much as digits as its factorization.

21022003243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 914000164.

The product of its (nonzero) digits is 576, while the sum is 19.

Adding to 21022003243 its reverse (34230022012), we get a palindrome (55252025255).

The spelling of 21022003243 in words is "twenty-one billion, twenty-two million, three thousand, two hundred forty-three".