21001103213 has 2 divisors, whose sum is σ = 21001103214. Its totient is φ = 21001103212.

The previous prime is 21001103191. The next prime is 21001103219. The reversal of 21001103213 is 31230110012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20984999044 + 16104169 = 144862^2 + 4013^2 .

It is a cyclic number.

It is not a de Polignac number, because 21001103213 - 2⁸ = 21001102957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21001103219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500551606 + 10500551607.

It is an arithmetic number, because the mean of its divisors is an integer number (10500551607).

Almost surely, 2^21001103213 is an apocalyptic number.

It is an amenable number.

21001103213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001103213 is an equidigital number, since it uses as much as digits as its factorization.

21001103213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 14.

Adding to 21001103213 its reverse (31230110012), we get a palindrome (52231213225).

The spelling of 21001103213 in words is "twenty-one billion, one million, one hundred three thousand, two hundred thirteen".