1678179066581 has 2 divisors, whose sum is σ = 1678179066582. Its totient is φ = 1678179066580.

The previous prime is 1678179066547. The next prime is 1678179066653. The reversal of 1678179066581 is 1856609718761.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1676066836900 + 2112229681 = 1294630^2 + 45959^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1678179066581 is a prime.

It is a super-2 number, since 2×1678179066581² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1678179066181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 839089533290 + 839089533291.

It is an arithmetic number, because the mean of its divisors is an integer number (839089533291).

Almost surely, 2^{1678179066581} is an apocalyptic number.

It is an amenable number.

1678179066581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1678179066581 is an equidigital number, since it uses as much as digits as its factorization.

1678179066581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30481920, while the sum is 65.

The spelling of 1678179066581 in words is "one trillion, six hundred seventy-eight billion, one hundred seventy-nine million, sixty-six thousand, five hundred eighty-one".