21221011001213 has 2 divisors, whose sum is σ = 21221011001214. Its totient is φ = 21221011001212.

The previous prime is 21221011001173. The next prime is 21221011001231. The reversal of 21221011001213 is 31210011012212.

It is a happy number.

Together with next prime (21221011001231) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14916758777284 + 6304252223929 = 3862222^2 + 2510827^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21221011001213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21221011001191 and 21221011001200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21221061001213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610505500606 + 10610505500607.

It is an arithmetic number, because the mean of its divisors is an integer number (10610505500607).

Almost surely, 2^{21221011001213} is an apocalyptic number.

It is an amenable number.

21221011001213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221011001213 is an equidigital number, since it uses as much as digits as its factorization.

21221011001213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 21221011001213 its reverse (31210011012212), we get a palindrome (52431022013425).

The spelling of 21221011001213 in words is "twenty-one trillion, two hundred twenty-one billion, eleven million, one thousand, two hundred thirteen".