1685106779 has 2 divisors, whose sum is σ = 1685106780. Its totient is φ = 1685106778.

The previous prime is 1685106769. The next prime is 1685106781. The reversal of 1685106779 is 9776015861.

It is a strong prime.

It is an emirp because it is prime and its reverse (9776015861) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1685106779 is a prime.

Together with 1685106781, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1685106769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 842553389 + 842553390.

It is an arithmetic number, because the mean of its divisors is an integer number (842553390).

Almost surely, 2^1685106779 is an apocalyptic number.

1685106779 is a deficient number, since it is larger than the sum of its proper divisors (1).

1685106779 is an equidigital number, since it uses as much as digits as its factorization.

1685106779 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 635040, while the sum is 50.

The square root of 1685106779 is about 41050.0521193335. The cubic root of 1685106779 is about 1189.9877076620.

The spelling of 1685106779 in words is "one billion, six hundred eighty-five million, one hundred six thousand, seven hundred seventy-nine".