21002011213 has 2 divisors, whose sum is σ = 21002011214. Its totient is φ = 21002011212.

The previous prime is 21002011211. The next prime is 21002011231. The reversal of 21002011213 is 31211020012.

Together with next prime (21002011231) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16366852489 + 4635158724 = 127933^2 + 68082^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002011213 - 2¹ = 21002011211 is a prime.

Together with 21002011211, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 21002011193 and 21002011202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21002011211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501005606 + 10501005607.

It is an arithmetic number, because the mean of its divisors is an integer number (10501005607).

Almost surely, 2^21002011213 is an apocalyptic number.

It is an amenable number.

21002011213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002011213 is an equidigital number, since it uses as much as digits as its factorization.

21002011213 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 13.

Adding to 21002011213 its reverse (31211020012), we get a palindrome (52213031225).

The spelling of 21002011213 in words is "twenty-one billion, two million, eleven thousand, two hundred thirteen".