1211997019 has 2 divisors, whose sum is σ = 1211997020. Its totient is φ = 1211997018.

The previous prime is 1211997013. The next prime is 1211997043. The reversal of 1211997019 is 9107991121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1211997019 - 2²⁷ = 1077779291 is a prime.

It is a super-2 number, since 2×1211997019² = 2937873548129772722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1211997013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605998509 + 605998510.

It is an arithmetic number, because the mean of its divisors is an integer number (605998510).

Almost surely, 2^1211997019 is an apocalyptic number.

1211997019 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211997019 is an equidigital number, since it uses as much as digits as its factorization.

1211997019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10206, while the sum is 40.

The square root of 1211997019 is about 34813.7475575382. The cubic root of 1211997019 is about 1066.1881481346.

The spelling of 1211997019 in words is "one billion, two hundred eleven million, nine hundred ninety-seven thousand, nineteen".