685105387 has 2 divisors, whose sum is σ = 685105388. Its totient is φ = 685105386.

The previous prime is 685105381. The next prime is 685105391. The reversal of 685105387 is 783501586.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 685105387 - 2¹⁹ = 684581099 is a prime.

It is not a weakly prime, because it can be changed into another prime (685105381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342552693 + 342552694.

It is an arithmetic number, because the mean of its divisors is an integer number (342552694).

Almost surely, 2^685105387 is an apocalyptic number.

685105387 is a deficient number, since it is larger than the sum of its proper divisors (1).

685105387 is an equidigital number, since it uses as much as digits as its factorization.

685105387 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 201600, while the sum is 43.

The square root of 685105387 is about 26174.5178943185. The cubic root of 685105387 is about 881.5611866018.

The spelling of 685105387 in words is "six hundred eighty-five million, one hundred five thousand, three hundred eighty-seven".