21221012003 has 6 divisors (see below), whose sum is σ = 21524114292. Its totient is φ = 20922119540.

The previous prime is 21221011961. The next prime is 21221012063. The reversal of 21221012003 is 30021012212.

It is a happy number.

It is not a de Polignac number, because 21221012003 - 2¹⁸ = 21220749859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21221012063) 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 5 ways as a sum of consecutive naturals, for example, 2099801 + ... + 2109882.

It is an arithmetic number, because the mean of its divisors is an integer number (3587352382).

Almost surely, 2^21221012003 is an apocalyptic number.

21221012003 is a deficient number, since it is larger than the sum of its proper divisors (303102289).

21221012003 is an frugal number, since it uses more digits than its factorization.

21221012003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4209825 (or 4209754 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21221012003 its reverse (30021012212), we get a palindrome (51242024215).

The spelling of 21221012003 in words is "twenty-one billion, two hundred twenty-one million, twelve thousand, three".