15505664 has 36 divisors (see below), whose sum is σ = 31806684. Its totient is φ = 7538688.

The previous prime is 15505661. The next prime is 15505687. The reversal of 15505664 is 46650551.

It can be written as a sum of positive squares in 2 ways, for example, as 6553600 + 8952064 = 2560^2 + 2992^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a nialpdrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 15505664.

It is not an unprimeable number, because it can be changed into a prime (15505661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8654 + ... + 10290.

It is an arithmetic number, because the mean of its divisors is an integer number (883519).

Almost surely, 2^15505664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15505664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15903342).

15505664 is an abundant number, since it is smaller than the sum of its proper divisors (16301020).

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

15505664 is an equidigital number, since it uses as much as digits as its factorization.

15505664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1690 (or 1676 counting only the distinct ones).

The product of its (nonzero) digits is 18000, while the sum is 32.

The square root of 15505664 is about 3937.7232000231. The cubic root of 15505664 is about 249.3619141045.

The spelling of 15505664 in words is "fifteen million, five hundred five thousand, six hundred sixty-four".