33166765781 has 2 divisors, whose sum is σ = 33166765782. Its totient is φ = 33166765780.

The previous prime is 33166765771. The next prime is 33166765783. The reversal of 33166765781 is 18756766133.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31380351025 + 1786414756 = 177145^2 + 42266^2 .

It is a cyclic number.

It is not a de Polignac number, because 33166765781 - 2⁶ = 33166765717 is a prime.

It is a super-2 number, since 2×33166765781² (a number of 22 digits) contains 22 as substring.

Together with 33166765783, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (33166765783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16583382890 + 16583382891.

It is an arithmetic number, because the mean of its divisors is an integer number (16583382891).

Almost surely, 2^33166765781 is an apocalyptic number.

It is an amenable number.

33166765781 is a deficient number, since it is larger than the sum of its proper divisors (1).

33166765781 is an equidigital number, since it uses as much as digits as its factorization.

33166765781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3810240, while the sum is 53.

The spelling of 33166765781 in words is "thirty-three billion, one hundred sixty-six million, seven hundred sixty-five thousand, seven hundred eighty-one".