1211311993 has 2 divisors, whose sum is σ = 1211311994. Its totient is φ = 1211311992.

The previous prime is 1211311967. The next prime is 1211312009. The reversal of 1211311993 is 3991131121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 672468624 + 538843369 = 25932^2 + 23213^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211311993 is a prime.

It is not a weakly prime, because it can be changed into another prime (1211311943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605655996 + 605655997.

It is an arithmetic number, because the mean of its divisors is an integer number (605655997).

Almost surely, 2^1211311993 is an apocalyptic number.

It is an amenable number.

1211311993 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211311993 is an equidigital number, since it uses as much as digits as its factorization.

1211311993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1458, while the sum is 31.

The square root of 1211311993 is about 34803.9077260011. The cubic root of 1211311993 is about 1065.9872388815.

The spelling of 1211311993 in words is "one billion, two hundred eleven million, three hundred eleven thousand, nine hundred ninety-three".