1998564085 has 16 divisors (see below), whose sum is σ = 2741961600. Its totient is φ = 1369907136.

The previous prime is 1998564049. The next prime is 1998564103. The reversal of 1998564085 is 5804658991.

It is a cyclic number.

It is not a de Polignac number, because 1998564085 - 2¹¹ = 1998562037 is a prime.

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, 93151 + ... + 112579.

It is an arithmetic number, because the mean of its divisors is an integer number (171372600).

Almost surely, 2^1998564085 is an apocalyptic number.

It is an amenable number.

1998564085 is a deficient number, since it is larger than the sum of its proper divisors (743397515).

1998564085 is a wasteful number, since it uses less digits than its factorization.

1998564085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22380.

The product of its (nonzero) digits is 3110400, while the sum is 55.

The square root of 1998564085 is about 44705.3026496858. The cubic root of 1998564085 is about 1259.6194544501.

The spelling of 1998564085 in words is "one billion, nine hundred ninety-eight million, five hundred sixty-four thousand, eighty-five".