685220087 has 2 divisors, whose sum is σ = 685220088. Its totient is φ = 685220086.

The previous prime is 685220051. The next prime is 685220111. The reversal of 685220087 is 780022586.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-685220087 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 685220087.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685220027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342610043 + 342610044.

It is an arithmetic number, because the mean of its divisors is an integer number (342610044).

Almost surely, 2^685220087 is an apocalyptic number.

685220087 is a deficient number, since it is larger than the sum of its proper divisors (1).

685220087 is an equidigital number, since it uses as much as digits as its factorization.

685220087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 53760, while the sum is 38.

The square root of 685220087 is about 26176.7088649433. The cubic root of 685220087 is about 881.6103807004.

The spelling of 685220087 in words is "six hundred eighty-five million, two hundred twenty thousand, eighty-seven".