21000221003 has 2 divisors, whose sum is σ = 21000221004. Its totient is φ = 21000221002.

The previous prime is 21000220999. The next prime is 21000221041. The reversal of 21000221003 is 30012200012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21000221003 - 2² = 21000220999 is a prime.

It is not a weakly prime, because it can be changed into another prime (21000221603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500110501 + 10500110502.

It is an arithmetic number, because the mean of its divisors is an integer number (10500110502).

Almost surely, 2^21000221003 is an apocalyptic number.

21000221003 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000221003 is an equidigital number, since it uses as much as digits as its factorization.

21000221003 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 11.

Adding to 21000221003 its reverse (30012200012), we get a palindrome (51012421015).

The spelling of 21000221003 in words is "twenty-one billion, two hundred twenty-one thousand, three".