1681617601669 has 2 divisors, whose sum is σ = 1681617601670. Its totient is φ = 1681617601668.

The previous prime is 1681617601627. The next prime is 1681617601673. The reversal of 1681617601669 is 9661067161861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1078918464100 + 602699137569 = 1038710^2 + 776337^2 .

It is a cyclic number.

It is not a de Polignac number, because 1681617601669 - 2⁷ = 1681617601541 is a prime.

It is a super-2 number, since 2×1681617601669² (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 (1681617602669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840808800834 + 840808800835.

It is an arithmetic number, because the mean of its divisors is an integer number (840808800835).

Almost surely, 2^{1681617601669} is an apocalyptic number.

It is an amenable number.

1681617601669 is a deficient number, since it is larger than the sum of its proper divisors (1).

1681617601669 is an equidigital number, since it uses as much as digits as its factorization.

1681617601669 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3919104, while the sum is 58.

The spelling of 1681617601669 in words is "one trillion, six hundred eighty-one billion, six hundred seventeen million, six hundred one thousand, six hundred sixty-nine".