1685221855 has 16 divisors (see below), whose sum is σ = 2054283264. Its totient is φ = 1326869280.

The previous prime is 1685221823. The next prime is 1685221861. The reversal of 1685221855 is 5581225861.

It is not a de Polignac number, because 1685221855 - 2⁵ = 1685221823 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 705994 + ... + 708376.

It is an arithmetic number, because the mean of its divisors is an integer number (128392704).

Almost surely, 2^1685221855 is an apocalyptic number.

1685221855 is a deficient number, since it is larger than the sum of its proper divisors (369061409).

1685221855 is a wasteful number, since it uses less digits than its factorization.

1685221855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4566.

The product of its digits is 192000, while the sum is 43.

The square root of 1685221855 is about 41051.4537501414. The cubic root of 1685221855 is about 1190.0147951459.

The spelling of 1685221855 in words is "one billion, six hundred eighty-five million, two hundred twenty-one thousand, eight hundred fifty-five".