1680869081 has 2 divisors, whose sum is σ = 1680869082. Its totient is φ = 1680869080.

The previous prime is 1680869077. The next prime is 1680869089. The reversal of 1680869081 is 1809680861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1260250000 + 420619081 = 35500^2 + 20509^2 .

It is an emirp because it is prime and its reverse (1809680861) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1806980891 and 1980896081.

It is a cyclic number.

It is not a de Polignac number, because 1680869081 - 2² = 1680869077 is a prime.

It is a super-2 number, since 2×1680869081² = 5650641734923569122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1680869089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840434540 + 840434541.

It is an arithmetic number, because the mean of its divisors is an integer number (840434541).

Almost surely, 2^1680869081 is an apocalyptic number.

It is an amenable number.

1680869081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1680869081 is an equidigital number, since it uses as much as digits as its factorization.

1680869081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 165888, while the sum is 47.

The square root of 1680869081 is about 40998.4033957421. The cubic root of 1680869081 is about 1188.9893452798.

The spelling of 1680869081 in words is "one billion, six hundred eighty million, eight hundred sixty-nine thousand, eighty-one".