211021021220921 has 2 divisors, whose sum is σ = 211021021220922. Its totient is φ = 211021021220920.

The previous prime is 211021021220899. The next prime is 211021021220929. The reversal of 211021021220921 is 129022120120112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 165777573215296 + 45243448005625 = 12875464^2 + 6726325^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211021021220921 is a prime.

It is not a weakly prime, because it can be changed into another prime (211021021220929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105510510610460 + 105510510610461.

It is an arithmetic number, because the mean of its divisors is an integer number (105510510610461).

Almost surely, 2^{211021021220921} is an apocalyptic number.

It is an amenable number.

211021021220921 is a deficient number, since it is larger than the sum of its proper divisors (1).

211021021220921 is an equidigital number, since it uses as much as digits as its factorization.

211021021220921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 26.

The spelling of 211021021220921 in words is "two hundred eleven trillion, twenty-one billion, twenty-one million, two hundred twenty thousand, nine hundred twenty-one".