211221061 has 2 divisors, whose sum is σ = 211221062. Its totient is φ = 211221060.

The previous prime is 211221037. The next prime is 211221077. The reversal of 211221061 is 160122112.

It is an a-pointer prime, because the next prime (211221077) can be obtained adding 211221061 to its sum of digits (16).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 181037025 + 30184036 = 13455^2 + 5494^2 .

It is a cyclic number.

It is not a de Polignac number, because 211221061 - 2¹¹ = 211219013 is a prime.

It is a super-2 number, since 2×211221061² = 89228673219931442, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211221091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105610530 + 105610531.

It is an arithmetic number, because the mean of its divisors is an integer number (105610531).

Almost surely, 2^211221061 is an apocalyptic number.

It is an amenable number.

211221061 is a deficient number, since it is larger than the sum of its proper divisors (1).

211221061 is an equidigital number, since it uses as much as digits as its factorization.

211221061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 16.

The square root of 211221061 is about 14533.4462877874. The cubic root of 211221061 is about 595.5420158100.

Adding to 211221061 its reverse (160122112), we get a palindrome (371343173).

The spelling of 211221061 in words is "two hundred eleven million, two hundred twenty-one thousand, sixty-one".