211021001 has 2 divisors, whose sum is σ = 211021002. Its totient is φ = 211021000.

The previous prime is 211020967. The next prime is 211021003. The reversal of 211021001 is 100120112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 125440000 + 85581001 = 11200^2 + 9251^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211021001 is a prime.

Together with 211021003, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 211021001.

It is not a weakly prime, because it can be changed into another prime (211021003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105510500 + 105510501.

It is an arithmetic number, because the mean of its divisors is an integer number (105510501).

Almost surely, 2^211021001 is an apocalyptic number.

It is an amenable number.

211021001 is a deficient number, since it is larger than the sum of its proper divisors (1).

211021001 is an equidigital number, since it uses as much as digits as its factorization.

211021001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 211021001 is about 14526.5619125793. The cubic root of 211021001 is about 595.3539320222.

Adding to 211021001 its reverse (100120112), we get a palindrome (311141113).

The spelling of 211021001 in words is "two hundred eleven million, twenty-one thousand, one".