21001100213 has 2 divisors, whose sum is σ = 21001100214. Its totient is φ = 21001100212.

The previous prime is 21001100179. The next prime is 21001100227. The reversal of 21001100213 is 31200110012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17039908369 + 3961191844 = 130537^2 + 62938^2 .

It is a cyclic number.

It is not a de Polignac number, because 21001100213 - 2¹² = 21001096117 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21001100194 and 21001100203.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21001100413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500550106 + 10500550107.

It is an arithmetic number, because the mean of its divisors is an integer number (10500550107).

Almost surely, 2^21001100213 is an apocalyptic number.

It is an amenable number.

21001100213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001100213 is an equidigital number, since it uses as much as digits as its factorization.

21001100213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12, while the sum is 11.

Adding to 21001100213 its reverse (31200110012), we get a palindrome (52201210225).

The spelling of 21001100213 in words is "twenty-one billion, one million, one hundred thousand, two hundred thirteen".