67756489661981 has 2 divisors, whose sum is σ = 67756489661982. Its totient is φ = 67756489661980.

The previous prime is 67756489661969. The next prime is 67756489661983. The reversal of 67756489661981 is 18916698465776.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67747039877881 + 9449784100 = 8230859^2 + 97210^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-67756489661981 is a prime.

It is a super-2 number, since 2×67756489661981² (a number of 28 digits) contains 22 as substring.

Together with 67756489661983, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 67756489661981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (67756489661983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33878244830990 + 33878244830991.

It is an arithmetic number, because the mean of its divisors is an integer number (33878244830991).

Almost surely, 2^{67756489661981} is an apocalyptic number.

It is an amenable number.

67756489661981 is a deficient number, since it is larger than the sum of its proper divisors (1).

67756489661981 is an equidigital number, since it uses as much as digits as its factorization.

67756489661981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6584094720, while the sum is 83.

The spelling of 67756489661981 in words is "sixty-seven trillion, seven hundred fifty-six billion, four hundred eighty-nine million, six hundred sixty-one thousand, nine hundred eighty-one".