1563649920 has 640 divisors, whose sum is σ = 6635059200. Its totient is φ = 343388160.

The previous prime is 1563649907. The next prime is 1563649939. The reversal of 1563649920 is 299463651.

1563649920 is a `hidden beast` number, since 1 + 5 + 636 + 4 + 9 + 9 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 11249211 + ... + 11249349.

It is an arithmetic number, because the mean of its divisors is an integer number (10367280).

Almost surely, 2^1563649920 is an apocalyptic number.

1563649920 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 1563649920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3317529600).

1563649920 is an abundant number, since it is smaller than the sum of its proper divisors (5071409280).

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

1563649920 is a wasteful number, since it uses less digits than its factorization.

1563649920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208 (or 187 counting only the distinct ones).

The product of its (nonzero) digits is 349920, while the sum is 45.

The square root of 1563649920 is about 39543.0135422175. The cubic root of 1563649920 is about 1160.6818029100.

It can be divided in two parts, 15636 and 49920, that added together give a palindrome (65556).

The spelling of 1563649920 in words is "one billion, five hundred sixty-three million, six hundred forty-nine thousand, nine hundred twenty".