211021210991 has 2 divisors, whose sum is σ = 211021210992. Its totient is φ = 211021210990.

The previous prime is 211021210979. The next prime is 211021211039. The reversal of 211021210991 is 199012120112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 211021210991 - 2¹⁴ = 211021194607 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211021210091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105510605495 + 105510605496.

It is an arithmetic number, because the mean of its divisors is an integer number (105510605496).

Almost surely, 2^211021210991 is an apocalyptic number.

211021210991 is a deficient number, since it is larger than the sum of its proper divisors (1).

211021210991 is an equidigital number, since it uses as much as digits as its factorization.

211021210991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 29.

The spelling of 211021210991 in words is "two hundred eleven billion, twenty-one million, two hundred ten thousand, nine hundred ninety-one".