21011212207 has 2 divisors, whose sum is σ = 21011212208. Its totient is φ = 21011212206.

The previous prime is 21011212193. The next prime is 21011212217. The reversal of 21011212207 is 70221211012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21011212207 - 2¹⁵ = 21011179439 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21011212217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505606103 + 10505606104.

It is an arithmetic number, because the mean of its divisors is an integer number (10505606104).

Almost surely, 2^21011212207 is an apocalyptic number.

21011212207 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011212207 is an equidigital number, since it uses as much as digits as its factorization.

21011212207 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112, while the sum is 19.

Adding to 21011212207 its reverse (70221211012), we get a palindrome (91232423219).

The spelling of 21011212207 in words is "twenty-one billion, eleven million, two hundred twelve thousand, two hundred seven".