1669979048581 has 2 divisors, whose sum is σ = 1669979048582. Its totient is φ = 1669979048580.

The previous prime is 1669979048561. The next prime is 1669979048599. The reversal of 1669979048581 is 1858409799661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1019714216481 + 650264832100 = 1009809^2 + 806390^2 .

It is an emirp because it is prime and its reverse (1858409799661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1669979048581 - 2⁷ = 1669979048453 is a prime.

It is a super-3 number, since 3×1669979048581³ (a number of 38 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1669979048561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 834989524290 + 834989524291.

It is an arithmetic number, because the mean of its divisors is an integer number (834989524291).

Almost surely, 2^{1669979048581} is an apocalyptic number.

It is an amenable number.

1669979048581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1669979048581 is an equidigital number, since it uses as much as digits as its factorization.

1669979048581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 235146240, while the sum is 73.

The spelling of 1669979048581 in words is "one trillion, six hundred sixty-nine billion, nine hundred seventy-nine million, forty-eight thousand, five hundred eighty-one".