33111131981 has 2 divisors, whose sum is σ = 33111131982. Its totient is φ = 33111131980.

The previous prime is 33111131969. The next prime is 33111132031. The reversal of 33111131981 is 18913111133.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19100622025 + 14010509956 = 138205^2 + 118366^2 .

It is a cyclic number.

It is not a de Polignac number, because 33111131981 - 2³⁴ = 15931262797 is a prime.

It is a super-2 number, since 2×33111131981² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (33111131951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16555565990 + 16555565991.

It is an arithmetic number, because the mean of its divisors is an integer number (16555565991).

Almost surely, 2^33111131981 is an apocalyptic number.

It is an amenable number.

33111131981 is a deficient number, since it is larger than the sum of its proper divisors (1).

33111131981 is an equidigital number, since it uses as much as digits as its factorization.

33111131981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1944, while the sum is 32.

The spelling of 33111131981 in words is "thirty-three billion, one hundred eleven million, one hundred thirty-one thousand, nine hundred eighty-one".