211221212051 has 2 divisors, whose sum is σ = 211221212052. Its totient is φ = 211221212050.

The previous prime is 211221212021. The next prime is 211221212071. The reversal of 211221212051 is 150212122112.

It is an a-pointer prime, because the next prime (211221212071) can be obtained adding 211221212051 to its sum of digits (20).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 211221212051 - 2²⁶ = 211154103187 is a prime.

It is a super-2 number, since 2×211221212051² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (211221212021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105610606025 + 105610606026.

It is an arithmetic number, because the mean of its divisors is an integer number (105610606026).

Almost surely, 2^211221212051 is an apocalyptic number.

211221212051 is a deficient number, since it is larger than the sum of its proper divisors (1).

211221212051 is an equidigital number, since it uses as much as digits as its factorization.

211221212051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 160, while the sum is 20.

Adding to 211221212051 its reverse (150212122112), we get a palindrome (361433334163).

The spelling of 211221212051 in words is "two hundred eleven billion, two hundred twenty-one million, two hundred twelve thousand, fifty-one".