15681216 has 112 divisors (see below), whose sum is σ = 44769024. Its totient is φ = 4832256.

The previous prime is 15681181. The next prime is 15681217. The reversal of 15681216 is 61218651.

15681216 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15681217) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 234015 + ... + 234081.

Almost surely, 2^15681216 is an apocalyptic number.

15681216 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 15681216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22384512).

15681216 is an abundant number, since it is smaller than the sum of its proper divisors (29087808).

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

15681216 is a wasteful number, since it uses less digits than its factorization.

15681216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158 (or 148 counting only the distinct ones).

The product of its digits is 2880, while the sum is 30.

The square root of 15681216 is about 3959.9515148547. The cubic root of 15681216 is about 250.2994598187.

Adding to 15681216 its reverse (61218651), we get a palindrome (76899867).

The spelling of 15681216 in words is "fifteen million, six hundred eighty-one thousand, two hundred sixteen".