211221212221751 has 2 divisors, whose sum is σ = 211221212221752. Its totient is φ = 211221212221750.

The previous prime is 211221212221741. The next prime is 211221212221757. The reversal of 211221212221751 is 157122212122112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211221212221751 is a prime.

It is a super-2 number, since 2×211221212221751² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211221212221757) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105610606110875 + 105610606110876.

It is an arithmetic number, because the mean of its divisors is an integer number (105610606110876).

Almost surely, 2^{211221212221751} is an apocalyptic number.

211221212221751 is a deficient number, since it is larger than the sum of its proper divisors (1).

211221212221751 is an equidigital number, since it uses as much as digits as its factorization.

211221212221751 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4480, while the sum is 32.

Adding to 211221212221751 its reverse (157122212122112), we get a palindrome (368343424343863).

The spelling of 211221212221751 in words is "two hundred eleven trillion, two hundred twenty-one billion, two hundred twelve million, two hundred twenty-one thousand, seven hundred fifty-one".