1563989856 has 144 divisors (see below), whose sum is σ = 4860222192. Its totient is φ = 437437440.

The previous prime is 1563989849. The next prime is 1563989881. The reversal of 1563989856 is 6589893651.

It is a self number, because there is not a number n which added to its sum of digits gives 1563989856.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 145830 + ... + 156186.

It is an arithmetic number, because the mean of its divisors is an integer number (33751543).

Almost surely, 2^1563989856 is an apocalyptic number.

1563989856 is a gapful number since it is divisible by the number (16) 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 1563989856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2430111096).

1563989856 is an abundant number, since it is smaller than the sum of its proper divisors (3296232336).

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

1563989856 is a wasteful number, since it uses less digits than its factorization.

1563989856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10405 (or 10386 counting only the distinct ones).

The product of its digits is 13996800, while the sum is 60.

The square root of 1563989856 is about 39547.3116153298. The cubic root of 1563989856 is about 1160.7659071875.

The spelling of 1563989856 in words is "one billion, five hundred sixty-three million, nine hundred eighty-nine thousand, eight hundred fifty-six".