71680037981 has 2 divisors, whose sum is σ = 71680037982. Its totient is φ = 71680037980.

The previous prime is 71680037921. The next prime is 71680038007. The reversal of 71680037981 is 18973008617.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68416772356 + 3263265625 = 261566^2 + 57125^2 .

It is a cyclic number.

It is not a de Polignac number, because 71680037981 - 2⁶ = 71680037917 is a prime.

It is a super-2 number, since 2×71680037981² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71680037921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35840018990 + 35840018991.

It is an arithmetic number, because the mean of its divisors is an integer number (35840018991).

Almost surely, 2^71680037981 is an apocalyptic number.

It is an amenable number.

71680037981 is a deficient number, since it is larger than the sum of its proper divisors (1).

71680037981 is an equidigital number, since it uses as much as digits as its factorization.

71680037981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 508032, while the sum is 50.

The spelling of 71680037981 in words is "seventy-one billion, six hundred eighty million, thirty-seven thousand, nine hundred eighty-one".