685950682181 has 2 divisors, whose sum is σ = 685950682182. Its totient is φ = 685950682180.

The previous prime is 685950682117. The next prime is 685950682217. The reversal of 685950682181 is 181286059586.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 429013210081 + 256937472100 = 654991^2 + 506890^2 .

It is a cyclic number.

It is not a de Polignac number, because 685950682181 - 2⁶ = 685950682117 is a prime.

It is a super-2 number, since 2×685950682181² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 685950682181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685950681181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342975341090 + 342975341091.

It is an arithmetic number, because the mean of its divisors is an integer number (342975341091).

Almost surely, 2^685950682181 is an apocalyptic number.

It is an amenable number.

685950682181 is a deficient number, since it is larger than the sum of its proper divisors (1).

685950682181 is an equidigital number, since it uses as much as digits as its factorization.

685950682181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8294400, while the sum is 59.

The spelling of 685950682181 in words is "six hundred eighty-five billion, nine hundred fifty million, six hundred eighty-two thousand, one hundred eighty-one".