1685221623 has 12 divisors (see below), whose sum is σ = 2437566768. Its totient is φ = 1121931360.

The previous prime is 1685221619. The next prime is 1685221649. The reversal of 1685221623 is 3261225861.

1685221623 is a `hidden beast` number, since 1 + 6 + 8 + 5 + 2 + 21 + 623 = 666.

It is not a de Polignac number, because 1685221623 - 2² = 1685221619 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1685221723) 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 in 11 ways as a sum of consecutive naturals, for example, 122238 + ... + 135323.

It is an arithmetic number, because the mean of its divisors is an integer number (203130564).

Almost surely, 2^1685221623 is an apocalyptic number.

1685221623 is a deficient number, since it is larger than the sum of its proper divisors (752345145).

1685221623 is a wasteful number, since it uses less digits than its factorization.

1685221623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258294 (or 258291 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 1685221623 is about 41051.4509244192. The cubic root of 1685221623 is about 1190.0147405372.

The spelling of 1685221623 in words is "one billion, six hundred eighty-five million, two hundred twenty-one thousand, six hundred twenty-three".