1220211191 has 2 divisors, whose sum is σ = 1220211192. Its totient is φ = 1220211190.

The previous prime is 1220211151. The next prime is 1220211211. The reversal of 1220211191 is 1911120221.

It is an a-pointer prime, because the next prime (1220211211) can be obtained adding 1220211191 to its sum of digits (20).

It is a strong prime.

It is an emirp because it is prime and its reverse (1911120221) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1220211191 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220211151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610105595 + 610105596.

It is an arithmetic number, because the mean of its divisors is an integer number (610105596).

Almost surely, 2^1220211191 is an apocalyptic number.

1220211191 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220211191 is an equidigital number, since it uses as much as digits as its factorization.

1220211191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 20.

The square root of 1220211191 is about 34931.5214526937. The cubic root of 1220211191 is about 1068.5913833844.

The spelling of 1220211191 in words is "one billion, two hundred twenty million, two hundred eleven thousand, one hundred ninety-one".