33749351981 has 2 divisors, whose sum is σ = 33749351982. Its totient is φ = 33749351980.

The previous prime is 33749351947. The next prime is 33749352001. The reversal of 33749351981 is 18915394733.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27117855625 + 6631496356 = 164675^2 + 81434^2 .

It is a cyclic number.

It is not a de Polignac number, because 33749351981 - 2²⁶ = 33682243117 is a prime.

It is a super-2 number, since 2×33749351981² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (33749351081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16874675990 + 16874675991.

It is an arithmetic number, because the mean of its divisors is an integer number (16874675991).

Almost surely, 2^33749351981 is an apocalyptic number.

It is an amenable number.

33749351981 is a deficient number, since it is larger than the sum of its proper divisors (1).

33749351981 is an equidigital number, since it uses as much as digits as its factorization.

33749351981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2449440, while the sum is 53.

The spelling of 33749351981 in words is "thirty-three billion, seven hundred forty-nine million, three hundred fifty-one thousand, nine hundred eighty-one".