8505999840 has 576 divisors, whose sum is σ = 31237871616. Its totient is φ = 1939931136.

The previous prime is 8505999829. The next prime is 8505999871. The reversal of 8505999840 is 489995058.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 87690672 + ... + 87690768.

It is an arithmetic number, because the mean of its divisors is an integer number (54232416).

Almost surely, 2^8505999840 is an apocalyptic number.

8505999840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8505999840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15618935808).

8505999840 is an abundant number, since it is smaller than the sum of its proper divisors (22731871776).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8505999840 is a wasteful number, since it uses less digits than its factorization.

8505999840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211 (or 190 counting only the distinct ones).

The product of its (nonzero) digits is 4665600, while the sum is 57.

The square root of 8505999840 is about 92227.9775339349. The cubic root of 8505999840 is about 2041.3076199347.

The spelling of 8505999840 in words is "eight billion, five hundred five million, nine hundred ninety-nine thousand, eight hundred forty".