15564489920 has 448 divisors, whose sum is σ = 47191818240. Its totient is φ = 4769280000.

The previous prime is 15564489907. The next prime is 15564489929. The reversal of 15564489920 is 2998446551.

It is a tau number, because it is divible by the number of its divisors (448).

It is not an unprimeable number, because it can be changed into a prime (15564489929) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 62009795 + ... + 62010045.

It is an arithmetic number, because the mean of its divisors is an integer number (105338880).

Almost surely, 2^15564489920 is an apocalyptic number.

15564489920 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 15564489920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23595909120).

15564489920 is an abundant number, since it is smaller than the sum of its proper divisors (31627328320).

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

15564489920 is a wasteful number, since it uses less digits than its factorization.

15564489920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 372 (or 362 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 53.

The spelling of 15564489920 in words is "fifteen billion, five hundred sixty-four million, four hundred eighty-nine thousand, nine hundred twenty".