211320220921 has 2 divisors, whose sum is σ = 211320220922. Its totient is φ = 211320220920.

The previous prime is 211320220913. The next prime is 211320220987. The reversal of 211320220921 is 129022023112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 148582495296 + 62737725625 = 385464^2 + 250475^2 .

It is a cyclic number.

It is not a de Polignac number, because 211320220921 - 2³ = 211320220913 is a prime.

It is not a weakly prime, because it can be changed into another prime (211320223921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105660110460 + 105660110461.

It is an arithmetic number, because the mean of its divisors is an integer number (105660110461).

Almost surely, 2^211320220921 is an apocalyptic number.

It is an amenable number.

211320220921 is a deficient number, since it is larger than the sum of its proper divisors (1).

211320220921 is an equidigital number, since it uses as much as digits as its factorization.

211320220921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

The spelling of 211320220921 in words is "two hundred eleven billion, three hundred twenty million, two hundred twenty thousand, nine hundred twenty-one".