15989664 has 48 divisors (see below), whose sum is σ = 42239232. Its totient is φ = 5296128.

The previous prime is 15989663. The next prime is 15989683. The reversal of 15989664 is 46698951.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (15989663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18097 + ... + 18959.

It is an arithmetic number, because the mean of its divisors is an integer number (879984).

Almost surely, 2^15989664 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 15989664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21119616).

15989664 is an abundant number, since it is smaller than the sum of its proper divisors (26249568).

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

15989664 is a wasteful number, since it uses less digits than its factorization.

15989664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1069 (or 1061 counting only the distinct ones).

The product of its digits is 466560, while the sum is 48.

The square root of 15989664 is about 3998.7077912746. The cubic root of 15989664 is about 251.9299376908.

It can be divided in two parts, 15989 and 664, that added together give a triangular number (16653 = T₁₈₂).

The spelling of 15989664 in words is "fifteen million, nine hundred eighty-nine thousand, six hundred sixty-four".