1563505640 has 64 divisors (see below), whose sum is σ = 3785985360. Its totient is φ = 578949120.

The previous prime is 1563505639. The next prime is 1563505663. The reversal of 1563505640 is 465053651.

It can be written as a sum of positive squares in 8 ways, for example, as 203518756 + 1359986884 = 14266^2 + 36878^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1563505640.

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, 22634 + ... + 60326.

Almost surely, 2^1563505640 is an apocalyptic number.

1563505640 is a gapful number since it is divisible by the number (10) 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 1563505640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1892992680).

1563505640 is an abundant number, since it is smaller than the sum of its proper divisors (2222479720).

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

1563505640 is a wasteful number, since it uses less digits than its factorization.

1563505640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37782 (or 37778 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 35.

The square root of 1563505640 is about 39541.1891576366. The cubic root of 1563505640 is about 1160.6461026083.

The spelling of 1563505640 in words is "one billion, five hundred sixty-three million, five hundred five thousand, six hundred forty".