21012021011213 has 2 divisors, whose sum is σ = 21012021011214. Its totient is φ = 21012021011212.

The previous prime is 21012021011131. The next prime is 21012021011239. The reversal of 21012021011213 is 31211012021012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19326767873284 + 1685253137929 = 4396222^2 + 1298173^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012021011213 - 2¹⁴ = 21012020994829 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21012021011191 and 21012021011200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21012021011713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506010505606 + 10506010505607.

It is an arithmetic number, because the mean of its divisors is an integer number (10506010505607).

Almost surely, 2^{21012021011213} is an apocalyptic number.

It is an amenable number.

21012021011213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012021011213 is an equidigital number, since it uses as much as digits as its factorization.

21012021011213 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 21012021011213 its reverse (31211012021012), we get a palindrome (52223033032225).

The spelling of 21012021011213 in words is "twenty-one trillion, twelve billion, twenty-one million, eleven thousand, two hundred thirteen".