211221221011901 has 2 divisors, whose sum is σ = 211221221011902. Its totient is φ = 211221221011900.

The previous prime is 211221221011777. The next prime is 211221221011921. The reversal of 211221221011901 is 109110122122112.

211221221011901 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 198486564852676 + 12734656159225 = 14088526^2 + 3568565^2 .

It is a cyclic number.

It is not a de Polignac number, because 211221221011901 - 2¹⁸ = 211221220749757 is a prime.

It is a super-2 number, since 2×211221221011901² (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 (211221221011921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105610610505950 + 105610610505951.

It is an arithmetic number, because the mean of its divisors is an integer number (105610610505951).

Almost surely, 2^{211221221011901} is an apocalyptic number.

It is an amenable number.

211221221011901 is a deficient number, since it is larger than the sum of its proper divisors (1).

211221221011901 is an equidigital number, since it uses as much as digits as its factorization.

211221221011901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 26.

The spelling of 211221221011901 in words is "two hundred eleven trillion, two hundred twenty-one billion, two hundred twenty-one million, eleven thousand, nine hundred one".