21212005603 has 2 divisors, whose sum is σ = 21212005604. Its totient is φ = 21212005602.

The previous prime is 21212005571. The next prime is 21212005673. The reversal of 21212005603 is 30650021212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21212005603 - 2⁵ = 21212005571 is a prime.

It is not a weakly prime, because it can be changed into another prime (21212005673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606002801 + 10606002802.

It is an arithmetic number, because the mean of its divisors is an integer number (10606002802).

Almost surely, 2^21212005603 is an apocalyptic number.

21212005603 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212005603 is an equidigital number, since it uses as much as digits as its factorization.

21212005603 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 22.

Adding to 21212005603 its reverse (30650021212), we get a palindrome (51862026815).

The spelling of 21212005603 in words is "twenty-one billion, two hundred twelve million, five thousand, six hundred three".