21213344003 has 4 divisors (see below), whose sum is σ = 21512123568. Its totient is φ = 20914564440.

The previous prime is 21213343993. The next prime is 21213344021. The reversal of 21213344003 is 30044331212.

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 21213344003 - 2¹⁸ = 21213081859 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 21213344003.

It is not an unprimeable number, because it can be changed into a prime (21213344023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 149389676 + ... + 149389817.

It is an arithmetic number, because the mean of its divisors is an integer number (5378030892).

Almost surely, 2^21213344003 is an apocalyptic number.

21213344003 is a deficient number, since it is larger than the sum of its proper divisors (298779565).

21213344003 is an equidigital number, since it uses as much as digits as its factorization.

21213344003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298779564.

The product of its (nonzero) digits is 1728, while the sum is 23.

Adding to 21213344003 its reverse (30044331212), we get a palindrome (51257675215).

The spelling of 21213344003 in words is "twenty-one billion, two hundred thirteen million, three hundred forty-four thousand, three".