15505566656 has 56 divisors (see below), whose sum is σ = 32586046080. Its totient is φ = 7304977152.

The previous prime is 15505566649. The next prime is 15505566667. The reversal of 15505566656 is 65666550551.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20015 + ... + 177233.

It is an arithmetic number, because the mean of its divisors is an integer number (581893680).

Almost surely, 2^15505566656 is an apocalyptic number.

15505566656 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 15505566656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16293023040).

15505566656 is an abundant number, since it is smaller than the sum of its proper divisors (17080479424).

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

15505566656 is a wasteful number, since it uses less digits than its factorization.

15505566656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157321 (or 157311 counting only the distinct ones).

The product of its (nonzero) digits is 4050000, while the sum is 50.

The spelling of 15505566656 in words is "fifteen billion, five hundred five million, five hundred sixty-six thousand, six hundred fifty-six".