1981133333 has 2 divisors, whose sum is σ = 1981133334. Its totient is φ = 1981133332.

The previous prime is 1981133311. The next prime is 1981133339. The reversal of 1981133333 is 3333311891.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1466660209 + 514473124 = 38297^2 + 22682^2 .

It is a cyclic number.

It is not a de Polignac number, because 1981133333 - 2¹⁶ = 1981067797 is a prime.

It is a Sophie Germain prime.

1981133333 is a modest number, since divided by 33333 gives 19811 as remainder.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1981133293 and 1981133302.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1981133339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 990566666 + 990566667.

It is an arithmetic number, because the mean of its divisors is an integer number (990566667).

Almost surely, 2^1981133333 is an apocalyptic number.

It is an amenable number.

1981133333 is a deficient number, since it is larger than the sum of its proper divisors (1).

1981133333 is an equidigital number, since it uses as much as digits as its factorization.

1981133333 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17496, while the sum is 35.

The square root of 1981133333 is about 44509.9239833096. The cubic root of 1981133333 is about 1255.9467748704.

The spelling of 1981133333 in words is "one billion, nine hundred eighty-one million, one hundred thirty-three thousand, three hundred thirty-three".