1981413173 has 2 divisors, whose sum is σ = 1981413174. Its totient is φ = 1981413172.

The previous prime is 1981413151. The next prime is 1981413193. The reversal of 1981413173 is 3713141891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1219266724 + 762146449 = 34918^2 + 27607^2 .

It is a cyclic number.

It is not a de Polignac number, because 1981413173 - 2¹⁰ = 1981412149 is a prime.

It is a super-3 number, since 3×1981413173³ (a number of 29 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1981413103) 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, 990706586 + 990706587.

It is an arithmetic number, because the mean of its divisors is an integer number (990706587).

Almost surely, 2^1981413173 is an apocalyptic number.

It is an amenable number.

1981413173 is a deficient number, since it is larger than the sum of its proper divisors (1).

1981413173 is an equidigital number, since it uses as much as digits as its factorization.

1981413173 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 38.

The square root of 1981413173 is about 44513.0674409212. The cubic root of 1981413173 is about 1256.0059072859.

The spelling of 1981413173 in words is "one billion, nine hundred eighty-one million, four hundred thirteen thousand, one hundred seventy-three".