21231221003 has 2 divisors, whose sum is σ = 21231221004. Its totient is φ = 21231221002.

The previous prime is 21231220973. The next prime is 21231221017. The reversal of 21231221003 is 30012213212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21231221003 - 2¹² = 21231216907 is a prime.

It is not a weakly prime, because it can be changed into another prime (21231221203) 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 as a sum of consecutive naturals, namely, 10615610501 + 10615610502.

It is an arithmetic number, because the mean of its divisors is an integer number (10615610502).

Almost surely, 2^21231221003 is an apocalyptic number.

21231221003 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231221003 is an equidigital number, since it uses as much as digits as its factorization.

21231221003 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21231221003 its reverse (30012213212), we get a palindrome (51243434215).

The spelling of 21231221003 in words is "twenty-one billion, two hundred thirty-one million, two hundred twenty-one thousand, three".