21038632213 has 2 divisors, whose sum is σ = 21038632214. Its totient is φ = 21038632212.

The previous prime is 21038632187. The next prime is 21038632249. The reversal of 21038632213 is 31223683012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21038632209 + 4 = 145047^2 + 2^2 .

It is a cyclic number.

It is not a de Polignac number, because 21038632213 - 2⁹ = 21038631701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21038632913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10519316106 + 10519316107.

It is an arithmetic number, because the mean of its divisors is an integer number (10519316107).

Almost surely, 2^21038632213 is an apocalyptic number.

It is an amenable number.

21038632213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21038632213 is an equidigital number, since it uses as much as digits as its factorization.

21038632213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 31.

The spelling of 21038632213 in words is "twenty-one billion, thirty-eight million, six hundred thirty-two thousand, two hundred thirteen".