1211221019 has 2 divisors, whose sum is σ = 1211221020. Its totient is φ = 1211221018.

The previous prime is 1211220991. The next prime is 1211221043. The reversal of 1211221019 is 9101221121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1211221019 - 2⁸ = 1211220763 is a prime.

It is a super-2 number, since 2×1211221019² = 2934112713734796722, which contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (1211220019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605610509 + 605610510.

It is an arithmetic number, because the mean of its divisors is an integer number (605610510).

Almost surely, 2^1211221019 is an apocalyptic number.

1211221019 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211221019 is an equidigital number, since it uses as much as digits as its factorization.

1211221019 is an evil number, because the sum of its binary digits is even.

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

The square root of 1211221019 is about 34802.6007505186. The cubic root of 1211221019 is about 1065.9605516884.

The spelling of 1211221019 in words is "one billion, two hundred eleven million, two hundred twenty-one thousand, nineteen".