211122211956421 has 2 divisors, whose sum is σ = 211122211956422. Its totient is φ = 211122211956420.

The previous prime is 211122211956391. The next prime is 211122211956457. The reversal of 211122211956421 is 124659112221112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 113603920688196 + 97518291268225 = 10658514^2 + 9875135^2 .

It is a cyclic number.

It is not a de Polignac number, because 211122211956421 - 2⁹ = 211122211955909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211122211951421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105561105978210 + 105561105978211.

It is an arithmetic number, because the mean of its divisors is an integer number (105561105978211).

Almost surely, 2^{211122211956421} is an apocalyptic number.

It is an amenable number.

211122211956421 is a deficient number, since it is larger than the sum of its proper divisors (1).

211122211956421 is an equidigital number, since it uses as much as digits as its factorization.

211122211956421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34560, while the sum is 40.

The spelling of 211122211956421 in words is "two hundred eleven trillion, one hundred twenty-two billion, two hundred eleven million, nine hundred fifty-six thousand, four hundred twenty-one".