1681617568877 has 2 divisors, whose sum is σ = 1681617568878. Its totient is φ = 1681617568876.

The previous prime is 1681617568849. The next prime is 1681617568907. The reversal of 1681617568877 is 7788657161861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 864725168836 + 816892400041 = 929906^2 + 903821^2 .

It is a cyclic number.

It is not a de Polignac number, because 1681617568877 - 2¹⁶ = 1681617503341 is a prime.

It is a super-2 number, since 2×1681617568877² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1681617568877.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1681617568817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840808784438 + 840808784439.

It is an arithmetic number, because the mean of its divisors is an integer number (840808784439).

Almost surely, 2^{1681617568877} is an apocalyptic number.

It is an amenable number.

1681617568877 is a deficient number, since it is larger than the sum of its proper divisors (1).

1681617568877 is an equidigital number, since it uses as much as digits as its factorization.

1681617568877 is an evil number, because the sum of its binary digits is even.

The product of its digits is 189665280, while the sum is 71.

The spelling of 1681617568877 in words is "one trillion, six hundred eighty-one billion, six hundred seventeen million, five hundred sixty-eight thousand, eight hundred seventy-seven".